Relationship help.

Hey y'all, I'm seventeen and I found this guy that I've fallen really hard and fast for and he has expressed that he fell for me too. I can't get him off my mind and as a result, i get wet often while thinking of him. I'm practicing abstinence and will be for the next two years hopefully, but i also want him to be my first. I don't know wgat to do because ge turns me on all the time... And I'm afraid to start birth control because of the weight I may gain. What should I do?I'm sexually frustrated 😞 please help.