Feeling overwhelmed and tired of everything

Hi everyone,
I'm 25 and from the UK. I'm not sure how to start this so sorry if it sounds awkawrd...
I'm really strugglinng but maybe it's my fault.
I haven't been working lately, but I've been applying for pretty much anything I think I could do at the moment.Back in June, I had a job, but then I messed up somehow. Basically, I really liked this woman at work-a total crush-and she seemed nice too. But she was with someone else which made things complicated.

Anyway, we started messaging on Snapchat and Facebook sometimes. Then one of my ex-friends (let's call her H) and this woman would hang out a lot because I got promoted to a higher position. We'd spend time together every day after work. It just became too much.

So, I decided to look for something better professionally since I thought with the skills and confidence boost from being promoted, it might be worth going for more challenging roles even if they were harder environments. But when I told some friends about an interview opportunity, it ended up reaching upper management who demoted me pretty quickly.

After that, my mental health took a hit. I felt like I worked really hard to get that promotion and being demoted felt unfair. Even though one supervisor said I could still use some benefits from the old position, they didn't explain much so I wasn't sure how it would work out in practice.

Then things got worse. After getting demoted, my mental health kept declining and I started reaching out more to that woman even thouh she was with someone else.

Sadly, I'm not confident at all-deeply insecure actually-and messaging her became obsessive. It eventually led to a very bad moment where I messaged her about something that happened in the smoking area and she got mad. A bunch of people started telling me off too. Even my supervisors said no one had ever reported any issues to them.

Now, I'm back living alone with no job and not many savings. While there are some future job prospects on the horizon, I have this feeling it won't last long.
I've done a few illegal things in the past, so mayybe one day it will catch up to me and then what? I don't know how I'll handle that.
I hoe to be better someday, but for someone like me, "coming out" about these things isn't something to celebrate...