@ticaaa,
So you went from putting your hand down her pants one night to giving her the silent treatment the next day. Even I'm confused as to what you're doing or wanting so I can understand how she's feeling.
Ok, let's try to figure this out.
You like her, that part is known. Now, here's the dilemma. Do you just want sex or do you want a girlfriend? You ACT like you just want sex but SAY you want her as a girlfriend. But she's already in a relationship. A shitty one, a long distance one, but still in a relationship.
You are confused because you tried putting the moves on her and she shot you down. Yet she continues to pester you with unsolicited pictures of herself, fully clothed. She wants something from you, and you're not sure what that is.
Ok, a stab in the dark -- maybe, just maybe she's a serial killer and wants to lead you out in the forest to have rituals on your behalf. Or a more reasonable explanation is -- she misses the friendship you two had. If you even had a friendship, I mean.
The world will never know! You won't talk to her!
So there it is in a nutshell.
I have to ask, what is your aversion to explaining what you want? You can have a conversation that goes like this:
"Hello Woman of My Dreams (Neil Young reference, look it up)
I apologize for my actions the other night. I went too far and I'm sorry. I understand you have a boyfriend and I respect that relationship. The problem is I like you more than just a friend, But until you're single, I can't be friends with you. Please stop sending pictures of yourself. It makes me feel uncomfortable to know I can't be with you, When your relationship status changes, I'd like to take you out for dinner and a movie."
That's an honest and sincere way of handling yourself. It shows you have the ability to wait for what you want and strength to walk away from a bad situation.
Try it. What do you have to lose?