Lots of good advice here. My advice is mostly a summary of what's been said and reading your comments.
save as much of that inheritance as you can. Doubling every 7 years with an S&P tracker is realistic.
don't buy a business.
minimize your outgoings.
if you're going to spend some of it, spend it on upskilling yourself. Take an inexpensive course in something that interests you.
Sounds like you might also want to spend some money on therapy or coaching and that would be ok but again don't overdo it.
if you want a career and you have the academics for it, look into consulting as you get to experience a wide variety of industries and project types.
nothing you pick now is permanent. The most interesting and happy people I know now have had multiple careers. Pick something that is interesting to you and throw yourself into it.
Lots of good advice here. My advice is mostly a summary of what's been said and reading your comments.
Good luck.