Take any help that the university offers, but you have to ask. It may well be split into pastoral support and academic advice, explain the projects that you are interested in and where you feel things have gone wrong for you. They can help with your mental well-being.
You may be able to defer your degree or, even at this late stage, go for a different topic.
However, it seems that the academic world is not for you...at the present time.
I feel that you should make a break. Find something worth-while that you want to do....if you want to stay in politics there are supporting/researching roles in organisations, as well as working as a researcher for MPs, or members of the House of Lords.
Otherwise discuss those topics you mentioned with someone who understands them and see if you can make a go of them.
Alternatively take a break and do something non-academic. A friend of mine dropped out of uni...became a mental health nurse for a few years, then decided he wanted to study zoology, did his degree and now runs a well known nature reserve, sometimes appearing on tv (Countryfile and the like).
You say that you want to be a success....only you can decide whether you are a success in your terms.
I speak as someone who got a third at uni....which academically wasn't much use to me. (I'd been very ill before finals, no revision and felt awful...I weighed less than 9 stone (57Kg) and I'm 6 foot tall (1.83m).)
However since then I've worked in environmental fields and made a difference to the world, and, in the water quality field, briefly became quite well known regionally and nationally as a result. However that was years ago and now, you would think we achieved nothing, given the campaigns underway now....but that's politics for you!
I've also studied with the OU, did a post-graduate diploma elsewhere (sponsored by my employer)...and as a result of that (and practical experience...which is always so important) got a job as a tutor at OU summer schools.
I've had a rotten time since COVID came along, with very few opportunities, but I start a new job in two weeks time...something I'm good at: talking to people promoting recycling.
In a nutshell: get the advice and support you need now. Then stay aware and take opportunities when they arise, some may not work out, but you will learn from them.
If you decide to return to academia, as others have said, there's the OU and similar types of courses if traditional universities don't appeal.
Don't dwell on the bad feeling of today...move on to some positive areas that you can concentrate on.