If you can't cope with A-levels, where you can retake bits you fail and you have schools telling you what to do, you might well struggle at university where you're treated as an adult and expected to organise your own work and the work is (or should be!) harder.
I'm likely to be getting CCC but I got an unconditional before I even took half of my A Level exams, it's all about individual talents/potential/prospects.
Employers nowadays don't usually look at the grades.
Work experience is more valuable than what you get in school/uni.
Tbh if you don't feel your doing well at the course you are taking now, why would you want to take it further? i find the things you do well in are the things your most passionate about, so perhaps try a new subject or something? and what course do you want to do at uni?
No. People want different things from an education and as long as a uni accepts you there is no reason you shouldn't go.