... Anyone have any personal anecdotes from a similar situation. Part of why it's so hard is because I am pretty lonely. I've struggled with drinking throughout my early 20s and I don't really have friends anymore as a result. The ones I do have won't care for hearing this. I like I'm on an island here. When we dated I really thought she and I would be forever, I even tattooed her name like an idiot. It's just hard.
I'd suggest you find professional help.
I also drank a lot in my 20's (and 30's) and while I was not losing friends over it, I did have drinking buddies I stopped associating with because I could see they were "problem drinkers," i.e. getting in legal trouble from drinking too much like DUIs and arrests, getting fired from their jobs because of absenteeism, or getting in bar fights and other stupid stuff.
In my experience it was usually not just drinking that was the problem: the people that struggled with it had other issues going on... that may be true in your case.
I don't know what else to tell you, and as far as getting over your ex, assuming the situation is as you describe, it should be clear to just about anyone that she's bad news and you should move on, so the fact that you can't see this, that you're struggling to get over someone who has repeatedly disrespected you... well to me that emphasizes the fact that you need some help to understand this.
It's not the fact that you made a mistake that's the issue here: it's that you repeatedly have made mistakes and don't seem to be learning from them. You should ask yourself why, and get a professional to help you find a path forward.
In the meantime, try to find ways to disconnect from these issues in a healthy way. Is there something you like to do that doesn't involve drinking or staring a screen? Like go for a run, walk in the woods, read, go for a swim, build model airplanes, draw, paint, etc. It doesn't have to be a big time commitment... just try for 15-20 minutes a day.
I myself had trouble disconnecting from screen time, and I'd find that if I could just tell myself to read for a bit first, it would often get easier. And I'd be happier with myself and feel good that I did it. (just as an example) and that self-confidence bump helped me in other ways too.