First year Maths student at a SHIT uni. HOW do I EARNMAXX?

I'm in the UK and just about to start a Maths degree at a completely unremarkable uni. I got 8s and 9s at GCSE with no revision, don't have anything else to show for highschool though, fucked up A Levels due to spiraling addiction. Just realised this sounds like satire but I'm serious lol. The addiction is irrelevant, I'm currently on a good enough streak but the point is I know I'm a very capable student, I just fucked up at a pretty important time of my life I guess.

I always loved maths, and I guess quant would be the most sensible option, but I know I'm competing with oxbridge grads and apparently the uni prestige is a thing in the industry? Idk what else in finance is as lucrative. Software eng also seems like a dead end, with only a few outliers really making bank.

I just want MONEY. What do I need to know to earn MONEY? I NEED to start off at AT LEAST 100K straight out of uni. I will literally put in 16 hour days for the next few years if it means I don't have to be a bottom feeder. Seems incredibly classist but I know most people could be doing much better if they had the right resources and support network. I just DON'T want to be that.

Getting sober ( for a month atleast) made me realise how many things in life are just mild distractions from major fuckups. I wanna clean up my fuckups. I know the next 3-4 years of my life could be the most impactful and I WILL make the most of them, but I'm starting from level 0. So advice?