This might be a little chaotic in response, but I am going to go through as quick as possible and share with you my feelings.
I can definitely understand your being more stressed and under pressure from school. Definitely when I was at college I had some pretty busy and stressful times. Sadly I actually regret that I didn't turn to the Book of Mormon or other scriptures more at that time to have a time to be edified. Missionaries want to check up on you to want to encourage you. No one is perfect and definitely us missionaries aren't perfect or best. Sometimes our meanings or our invites and desires can come across in the wrong way. Especially when we have come from different backgrounds and cultures.
There desire is that an early time in your life you can develop the habit of turning to the scriptures not just to read because it is told to be read. But rather that you have the desire to turn to it because you are seeking comfort, you are seeking peace, you are seeking answers, or that you may be strengthened. Same with prayer. The encouragement or very much the constant reminders come now so that in your future when the trials and challenges come where you are utterly alone, when you are backed against the wall and your faith is tested, when you will need to make a choice between standing with God or forsaking him, you will have already solidified and fortified your faith through constant nourishment of the word of God that you won't think twice about your decision to always stand with God.
Of course it comes completely to your decision how and when you wish to come closer to God. That is one of the greatest and best parts but also sometimes one of the most frustrating and hard to understand parts in this life we have and the plan Heavenly Father has prepared. Agency is given to every single person. Missionaries and others reach out so much, encourage so much, and follow up so much because we have felt these things to be true. We know them to be true. We understand and know Heavenly Father's plan. We understand that death is not the end. But that when death comes and we haven't lived according to God's laws and done the things He has required of us in this life, it will be very difficult if not impossible to change our choices and actions and thoughts after death (particularly if we had learned and heard of Jesus Christ and his Restored Gospel and chose to reject it). That is why with so much vigor and energy that missionaries or others call out to you and encourage you. I myself have passed through some very hard, very lonely, very miserable, very hurtful trials and sins. Having to live with some of the consequences of those sins is not easy. But through Christ I have obtained so much peace and calm in my life. This is what I desire and wish to share with you, with everyone that I meet. To warn them, to protect them, to help them to not go down some of the paths I have already trodden. To help point them to this peace, this comfort, this calm, to eternal life.
I also yes realize that you are not 20 yet and through much of your expressions how that your parents in very large parts oppose getting baptizing or any association with church. I also realize and understand the missionaries push to try and be baptized before 20. It is because Satan, the enemy to God and all righteousness, is not going to rest easy with your desire to be baptized or to come unto God or to join His true church. He will work harder than ever throwing any and all temptations, doubts, and uncertainties at you. I will share with you about a man named TTT. I met him in my first area here in Taiwan. He had a testimony, he truly had received answers that the Book of Mormon was true, and desired more than ever to keep God's commandments and be baptized. He was not 20 yet. His mother opposed him being baptized. We tried everything we could to help in overcoming the opposition. But the mother never let up. He went to college then in Taibei. He very seldom came back. Then one day shortly before my companion was going to go home he felt impressed to call him. He talked with him and found that when he was at college he didn't go to church, he wasn't reading or praying, had met some Buddhist information and brochures, and now questions everything he had learned, felt in his soul, and received answers. I don't know how he is now. But it broke my heart to see a man who left so determined with a knowledge of the truth to completely doubt everything and no more have a desire to be baptized. That is why they push hard on trying to be baptized, because very much there are many forces from the devil that are working against you and not wanting you to receive these special and specific blessings.
I will never have the experience and understanding of having family opposition to what I desire to believe and follow. When we come to a knowledge of the truth though. That when we know that God exists and that He is real, has a perfect body, and knows each and every single one of us. When we know there is a plan provided for us to live eternally. That the authority to enable this gift exists on the earth today in the Church of Jesus Christ of Latter Day Saints. Then we cannot deny it, we cannot turn back, or we turn our back on God and everything that He has given us. We at times need to be bold and courageous. We don't argue or ridicule or criticize others or their beliefs. But we do need to stand for truth, stand with Jesus Christ, and even if that means we need to stand alone. There is a talk by President Thomas S. Monson from the General Conference a few weeks ago. I believe it was in the Priesthood Session that he shared specifically about being courageous and doing what is right. I strongly encourage to take the 10-15 minutes in your day to read through this talk. It will help to bolster and uplift your own faith and courage.
God has created us in His image, Man and Woman, so that they may be joined together in marriage and rear families. There is a reason that only a man and a woman can create life and bring a child into this world. It is how God has established it and provided for the greatest joy, peace, and happiness to be obtained in this life and in eternity. Through the family reared and headed by husband and wife, man and woman. There is an article the the Prophet, First Presidency, and the Quorum of Apostles came out with 14 years ago. It is called "The Family: A Proclamation to the World". I also strongly encourage you to read this (also about 10-15 minutes). I promise as you take the time to read this it will help you to better understand and bless you more than ever. It will give you a chance to take a break from all the studies and I know that God will see your efforts and desires and will bless you in your life more than ever, especially in recalling and remembering all that you have studied for your midterms.
Lastly I have never felt more than on my mission the blessing that comes from attending church. It has touched and transformed my life more than ever. I have felt it uplift my life, help to soften my heart, to heal an aching and broken heart. Don't give up now. Go and ponder. Pray to God, the one who understands your situation more than anyone else and will help you to overcome, face, and triumph the challenges and trials that are in your life at this time.
My time is up, but pray earnestly that you will ponder on the things I have shared as well as others. Pray over these things. Remember the answers and the truth you have felt in your heart.
I hope all is well with you and that your future will be even greater!