Someone Discuss This With Me. Please

I have been anonymously leaving messages on the girl I like's tumblr. I've known her for years and liked her just as long. 

She's absolutely perfect in every single way. Funny (in the brilliantly clever and witty sort of way), talented (at everything -art, music, writing, etc), intelligent (wittily so, and book smart too), adorable (god, the faces she makes), beautiful (genetics have seriously worked in her favor), interesting (she has so much to say about everything), and so much more. 

I think she knows it's me leaving the messages- I've been leaving little hints as to my identity. 

We cuddled yesterday and fuck, it was perfect. 

She's invited me out today. I think the subject of the messages will come up. 

And I was thinking. If she feels the same, what the fuck do I do about my boyfriend. 

We started hooking up last year, then dated. I broke up with him, then got back together with him months later. I never really and actually liked his personality until lately. 

I've described him many times in past journals. But, basically, he's rude, arrogant, loud, dramatic, bitchy, drinks too much, and can get violent. 

But he's grown on me. I actually care about him a bit. And lately he's been having a rough time with work and family and everything and I want to help. 

But now what? As soon as some girl likes me, I'm supposed to just dump him? 

I know the right thing to do is break up with him and date her. 

Obviously I can't cheat on her. Not her, of all people. 

But. I also feel like I can't break up with him. Again. 

It feels wrong. Like betrayal. 

I know he loves me. He's told me. And I can feel it in the way he touches me and kisses me. 

And I don't love him. But, I don't think I love any living thing other than my cats. 

But I feel like I'm already practically in love with her. 

I know I should see how things pan out with her, then make a decision. 

But I can't stop thinking about how much I'll be screwing him over yet again, about how I'll be the heartless bitch yet again, about how I'll break his heart yet again.