I need serious advice.

Sorry guys, it's my first time here. Given the circumstances of my relationship, I believed it would best fit this category. Sorry if I am incorrect.

I've been in a [lesbian] long distance relationship for over 2 years now. The person I'm with, I really have strong feelings for, but being young, stupid and inexperienced has caused some frustrating issues. Our relationship is taken seriously by all means.

She's just turned 19. I'm 15, turning 16 in May. I have known her since I was 12 and she and I have had a high level of trust within each other, until last year.

My best friend got tired of her sexual fantasies with me and decided to lash it out on her. I mistook her comments for someone else, and so I profusely apologised to my girlfriend. Not only that, later (like a few months) I pulled a really stupid move that I don't have a motive, let alone a clear understanding for. I cheated on her through a sexual roleplay in a chat, which has caused her to lose almost all of her trust in me. I deeply regret it and I don't know how to fix things.

Only later today did things get worse on my end. She confessed that other than pain, all she could get out of our relationship wasn't just pain, but sex. I appreciate her honesty, but now I don't know what I'm supposed to feel.