I'm not a normal person so please just don't get angry.
If I understood the whole thing right, and I honestly didn't have the same thing going on in my life, only some similar, there is not much to say.
You won't get rid of emotions easily, not even if your brain kicks in the rational part. The part that says I don't need her, she doesn't need me - I don't bring her food, neither does she to me, why the fuss then.
There is no cookbook recipe here to deal with the pain. It's the type of a wound only time heals. So give it time. That's it, yes, I know I didn't help much. But when your thoughts return to it, let them through, let them roll, don't resist. Eventually they'll stop by themselves.
The thing is, everything comes back. Rarely anyone believes that, but it does.
It won't happen when you expect it, it will happen when you completely forget (and you will). Your friend, will eventually realize what she had lost. And will try to get you back.
Make the refuse card today and put it somewhere deep inside to use when the time comes.
You're in the time of need. A friend who doesn't understand that, and that's her, is not a friend at all. There is no excuse, a friend, even when angry with you, when disappointed, when mad, will still be a friend. Get out of your house, for a walk, for a coffee, for anything and meet some other random people. People you didn't notice before and people you did notice but didn't have time to chat with because… Well… Things like needs of your friend got in the way.
Yes I'm saying get a bit more selfish.
For the second part…
Get a job with decent income, it doesn't matter which one, a job is a job. If on your side cleaning streets or working in mortuary pays well, who cares, grab it.
After that, move out in some dump. Not a decent place, get a dump. You still need that experience. The side effect? A real friend won't mind you living in a dump and in fact will help you with paintjob and stuck windows (when possible).
As I said, I'm not a normal person so I just can't talk as if I was. I'm just saying what I'd want to hear from people if I was in your shoes.