Hello Miss Paige, you did the right thing in reaching out.
Sexual peer pressure can be a very heavy burden, but your boyfriend is not exhibiting very much respect for your choices. if he has repeatedly asked you for sex even after you have turned it down, then he is trying to work down your defenses and "talk you into it". He probably is not concerned with your feelings of sex, he just wants it. So a very firm "No." is the answer to your question. You do not "just give in", it is your body and it is your decision when and if you share it with him. You are not obligated to do so just because you gave him the "boyfriend" label. He does not have a right to have sex with you, and you are not obligated to give him sex if you do not want to.
It would be in your best interest to take a trusted friend with you the next time you speak to your boyfriend and tell him assertively that you do not want to have sex and that he is to stop asking you for it after you have given him your answer. Do not be concerned if he breaks up with you for asserting your decision with him. You are a human being and have every right to feel secure in your own boundaries, and you have every right to tell someone to back off if they are taking advantage of being allowed inside your personal boundary.
I hope this has given you the perspective that you need to come to a solution. Please keep in contact and let us know how things progress, always remember that you matter, and you are not alone.