VIRGIN PLEASE HELP

So I’ve been masturbating for a while now and EVERY time I orgasm. Now that I have my first boyfriend that I’m doing sexual things with, I can’t even remotely get turned on by porn any more. I am a virgin and that’s going to change soon and I wanted to masturbate using penetration for the first time to get used to the feeling since my boyfriend is on the bigger side. Has this happened to anyone and if so what did you do?