To be honest it surprises me that quite a few people consider making such a big decision by asking strangers on a forum. That isn't to say that you won't get good advice here, you may, but
you may also get some irresponsible advice from people that don't really give a damn. What you want to do now (i.e. become a trader), may not be what you want to do next year or in 5 years. You are quite young if you are just finishing your A-levels, and your perspective will probably change more than you can imagine.
My opinion, for what it is worth, is that if you can get a place at a decent university, doing a course you are interested in, you should do it without hesitation. Probably very little of what you will learn at university will help you in trading (or in your future job whatever that is for that matter), but the mere fact of you having a degree will open some doors for you. If you can get a 2:1 or 1st from a top university, so much the better. Having a university degree can mean that you get paid more than someone doing exactly the same job. And anyway, university can be a great experience in itself.
If you love trading, you will still have plenty of time to do that while a student.
Most students aren't working 40-50 hours+ a week, so you will have time on your hands to practice trading and learn if that is what you want to do. Again, what you want to do may change a lot, so try to keep your options open. And for me, a university degree will give you more options.
have been using a practice account on ETX Capital for nearly a year now and my trading has improved significantly.
Trading on a practice account is not the same as trading for real, and even though you have improved on the practice account, you still have yet to find out if you have improved when money is on the line. Also improvement could be getting to break-even, or even losing a lot less
. I don't know at what level you are at, but you have to consider whether you can
realistically make enough money to support yourself in the next years. Good luck with whatever you decide.