This is just my experience so take what you want from it.

I struggled for a long time getting a little better and then falling backwards, and I was seeing a psychiatrist, doing therapy, and attending AA.

But what I wasn't doing was staying sober long terrm. I'd stay sober for a few months, then relapse and undue all the good I'd managed.
Then I had what turned out to be my last relapse. I got so sick and the withdrawal was so bad that I pretty much determined I couldn't life through another one and I made up my mind to do whatever it took to stay sober, today. And that's all I focused on - staying sober. And I did.

And my life started to improve. I started volunteering. Then I got a part time job. My mental health started really improving and I was able to get off some of my meds which increased my energy levels so I was able to do more positive things for myself. Then I was able to get into stable housing. Then I got a second part time job and more hours at my first job so that I'm now basically working full time hours.

My life isn't perfect, but that's ok. Most of the time I'm happy and like my life. I'm helping people in my jobs, I'm 5 1/2 years sober and I wouldn't go back to drinking for anything.

I know you struggle with substances and mental health too. So is there hope, yes. I believe that as long as you have a pulse there's hope. But for me, I had to get and stay sober first, before I could make the changes to significantly improve my life.