I think you’re a little confused about things, too. You miss the friendship, and yet, to punish her, you want to refuse to be friends with her as a condition for having sex with her. That’s messed up.
It sounds to me like you would like to have a real relationship with her as long as she could accept your friendship at the level you can provide it to her. You don’t mention what it was that she expected and you couldn’t deliver, but that must be the crux of the issue.
You are effectively negotiating over this without actually saying you are negotiating over it. As a result, you are lashing out and withholding in a very codependent manner. I’m surprised my friend “I see codependency everywhere” @Coloma didn’t call that one, but I will.
I think you both like each other and love each other, but this issue of expectations is too much for you to handle on your own. You’ve decided to break it all off since you don’t know how to negotiate a better deal. She’s trying to get you to come back and talk, since she knows there’s enough there to create a good relationship. You’re angry with her, and are trying to punish her in an attempt to get her to reduce her demands, and then you ask us what you are doing, because you don’t understand what you are doing.
I think you are in over your head. I think you’d like a relationship with this woman if it could be slightly less intense. If these expectations could be reduced. Whatever they are.
I think you guys can’t handle this on your own. So what will happen is you will cut it off because you don’t have the skills to fix it.
The only thing I can think is that you need professional relationship help. You need someone to cut to the chase here, i.e., what she expects that you can’t find a way to successfully reduce and make livable. Then you need to focus on this area and be very practical. What do you want? What does she want? What can you give? What can she give? Negotiate a practical solution.
It’s an alternative. Frankly, I doubt it is a doable alternative. Most people your age (I’m guessing your are in your 20s) won’t get professional help. You might not even have insurance that covers it. You can also go to couples workshops that might be affordable, depending on what part of the country you live in.
So, what will happen if you stay in this fwb relationship without help is that you will keep engaging in the codependent circle. Push me, pull you. One withdrawing, the other pursuing, then switch roles. It will go until you can’t stand it any more and you really do cut it off. You may have to go through this in order to really believe you need to cut it off. But the end, if you do not change the pattern, is inevitable.
Or you could change the pattern. Read about codependent relationships. Learn techniques to break the pattern. See a therapist or go to a couples workshop to learn how to change things. Then you’ll have a chance. If it’s worth it, you’ll give it a chance. But if you go it alone, it’ll be over in six months or less, is my bet.