I think I may have fucked up my relationship beyond the breaking point and I don't know what to do.

For context:

I have been with this person for almost 5 years. I have an engagement ring. I have not proposed yet, but we have discussed it. We also live together.

A couple of years ago I went down a massive fucking spiral due to drug addiction. It almost broke us, but I managed to break the addiction.

Then earlier this year I lost my job. I was laid off suddenly, and lost my insurance immediately. I was left with out therapy until two months ago (after the probationary period for my new job was over). I started to spiral down again.

My partner has several autoimmune diseases that seem to have been set off by a mix of past trauma and dealing with me during the drug-induced spiral.

I've also just started some new medications.

---------

Today.

I split, and I split hard. She was just trying to tell me that I was being passive aggressive and short with her all day (which was true, but it wasn't out of anger - it was out of me just being depressed). I tried to explain this to her, except by explain it to her, I really just started to yell that I wasn't mad at her and it was just cause I was so depressed, and it started an insane screaming match that resulted in me saying the following awful things.

1. You don't care about me.
2. You ruined my life.
3. You are the reason I want to kill myself.
4. I will be dead if I stay with you.

She is, needless to say, extremely hurt and angry about this. I've spent the last couple hours trying various ways to communicate I didn't mean those things, but she doesn't believe me due to a problem I have with inconsistencies and not always being the most honest person.

I don't feel like myself. I don't feel like this is me. The person that I've been for the last six months or so has been destroying my life and I'm so fucking done with it. I can't seem to snap out of it, but I don't know where to go.

If we break up, I don't have a place to live to recover. I lose my job, I lose my insurance, I lose all of my support system.

But more importantly, I lose her. I don't want to lose her. I don't want this fucking monster that seems to be inside of me to ruin the best thing that's ever happened to me. And she is the best thing that's ever happened to me.

I don't know if it's possible to fix it at this point. But I will try literally anything at this point.