How did u turn your life around at 30?

I'm fortune enough that it's not something I've had to do, but my dad taught a lot of people who did do it through the Access to HE diploma. That sounds like it could be a good fit for you. It's a one year full time or two years part-time level 3 course aimed at mature students, instead of A-levels. It's intense, but you get a lot of support to help you return to full time education. It has a high non-completion rate but the students who are successful with it are people who left school some years ago and whose lives have changed, or who have made changes in their lives since that time.

I got married. Marriage is a correctional institution.

consider joining the military. in the british army, you can enlist as high as 36. as long as you have no criminal record, can be in shape, no medical issues, you should be qualified to serve. but see a recruiter either way, only they can clear you for enlistment.

i'm sure they have hundreds of jobs that aren't all combat or infantry related. and some could probably find similar careers when your service is over.

https://apply.army.mod.uk/how-to-join/can-i-join

https://apply.army.mod.uk/roles

look at other branches too and see what they all have to offer.