Pushing away the girl I wanted to marry

Been friends with this girl for 10 years, best friends, tell eachother things we can't tell anyone else. It's cliche but we finish eachothers sentences, we know what we're thinking and don't even need to say it sometimes.

She has a promising career, is about to start making a LOT of money, she worked very hard for it and I couldn't be more proud of her. I have no career, never went to college, I just work at whatever place I work for at the time and make enough money to not be homeless and still stay poor, it's my fault and nobody else's. In fact, she's the absolute least materialistic girl I've ever met, to her money is a means to make the people she cares about happier.

We live far apart, but we've gotten much closer than ever before in the last couple of years, joked about getting married if we're still single in 10 years, then it became 5, then 2, then we stopped joking and just starting talking about it casually like "once we're married we'll go here and do this"

I have depression, I've had it since I was a kid, It gets worse sometimes, sometimes...really bad. I've lived my life with 1 foot out the door because of it

Every friendship, every relationship, I love with my whole heart, but I tell myself they'd be better off without me for one reason or another, and I'm always ready to leave as soon as they might tell me to

The last few months I've been..happy I think

It was because of her.

Then during a time where i was in a major depressive episode and very stressed from life throwing everything it could at me, I told her it's never going to happen. That ill never let us be together. Never. No matter what she says or does I've made up my mind for her benefit because I love her so much I don't want to drag her down with me

She cried. Hard. I've never hurt her before, it felt like a knife in my chest.

Eventually we talked it all through and things were okay, then she was going to hang out with a friend she's known for a few years from work, I knew they were going to hook up because it was far from home and they were going to spend the night in a hotel

I didn't say anything to her because who am i to be bothered by that, when I made it clear we'd never be together

They did hook up, she didn't tell me at first, felt guilty, eventually told me and I told her I knew already

She's very sad about it, says she wishes I'd stop, that we could be together, that she wants to date me, that she loves me, always

I keep saying the same thing, I'm not good enough, hell I don't even know if I'll be alive a month from now

We're in a better place now, it's been about a month. She's dating but says she's judging guys by my standards, if they don't treat her the way I did she doesn't give them a chance

Still feels like that knife is in my chest, only it's twisting now

I still know I have no right to be upset with her, she'd date me if I told her I wanted to, I just refuse to do that to her. She deserves better even if she says I'm stupid for thinking that way

She's my best friend, I want to spend time with her, talk to her, but after a while my mind drifts to what happened, what's happening still, the way I hurt her, the things that could be different if I cared about myself enough to get better 10 years ago when we met

I gave up on myself then, I'm trying not to now, I have friends who love me and I know they'd be hurt if I died, but I just....don't know how much longer I can take this