There is a smart solution to all of this, but it is a bit "out there". Don't go to university (yet) and don't make any decisions (yet) about your future career. You are not alone. I would say the majority of sixth form leavers don't really have a plan. The problem you have is that you have absolutely no context on what your future life will be like so why on earth would you be able to choose? Even those who do have dedicated career aspirations often hit their goals only to find they were not as intended.
So take some time out. You don't have to go straight to university. Instead, get a job. Do some travel. Join a hippy commune. Talk to lots of people about it. But do spend some time figuring out the next step. Since university is such a huge financial commitment, there is nothing to be gained by going there "just because" and hoping for the best.
Rather than focussing on long term career aspirations, set short term goals. If university is definitely the way forward, ensure you choose a course that you will really enjoy. And spend a load of time ensuring you will enjoy that course. You only get one chance (unless your folks are loaded) so take the time to make the most of this once-in-a-lifetime opportunity.
The very best of luck!