With crim/psych, you can do all sorts of things - probation, youth justice, prison service, police, civilian police employee, civil service, third sector: the sky's your limit! The only thing is, if you want to do more psych-type stuff specifically, you will need to do post-grad study: but you're in a good place to do anything in the criminal justice sector, never mind other jobs that will appeal.
There's loads of options- have a bit of a google, and see what you fancy! You will be a more appealing candidate than you seem to be giving yourself credit for - you've worked really hard to push yourself out of your comfort zone to help tackle your anxiety (by managing to get on the bus and go to your group - form memory, I think you posted a while ago that you struggled to go previously, even with a support worker: don't minimise how far you've come). You've also done a degree - it's actually harder in a lot of ways to do OU, because you need to be far more independent than someone studying full-time conventionally. You've shown you've got commitment, and that you can organise your time.
How about having a look at getting some experience by volunteering with your nearest YOT? (assuming you are interested in YJ) - details here
Or if you're more interested in issues like DV, have a look into your local support groups - the same for refugee/asylum issues: people are often crying out for volunteers - everyone wants to volunteer Christmas Day, but they are short of people all year round.
There's options for working with offenders [[https://www.workwithoffenders.co.uk/ here]
I know you're feeling lousy, and it's hard to work towards a change when you are: but it really doesn't have to be this way for the rest of your life if you don't want it to. Volunteering's a good way to meet new people, get out of the house (even if it's hard at times, it's "easier" than just going to the shops, because you've made a commitment to someone else and won't want to let them down) and get some experience that might help you decide what to do.
Anxiety can be a vicious cycle, I know - the less you do, the less you are able to do: and look at how you far you've already come, going to your group on your own, and even reaching out to someone else. (Fwiw, she might not be ignoring your message - people calling or texting me makes me very anxious - so my mobile has been off since the middle of November!) You can do this - if you want to. I know it's hard to break the cycle of negativity: it took me ages. I started off by challenging every time I said something negative - "I always have bad luck, nothing ever goes right" and turning it round. So if I'd just missed the bus, and it was raining, and there wasn't another one for half an hour - instead of telling myself this always happens, I'd remind myself that I'd got a bus in two minutes in the morning, and I was a lucky person, so another bus would be along in a minute, even though it wasn't scheduled. Objectively, this has no impact on buses whatsoever - but believe me, little by little it ends up changing how you view yourself.
You can be the architect of your own destiny: yes, things have been tough for the last 25 years - but are you going to let a bad start influence the next 60 years of your life, or are you going to kick fate in the balls, say fuck you, and start having the life that you deserve?