Number one on your list appears to be leave uni, get a job and save up for pilot training. What kind of job are you expecting to get? Do you have any experience? At your age I doubt it, so with no experience, and no degree, any job you get is not going to be fantastically well paid. I think you'd be lucky to cover bills and rent, never mind manage to save up £40k+. Just think, you need at least £5k for your PPL, if you try to save this over a year, that's over £400 a month you need to put away. Go and do some sums!
If you take a year out, you will never go back to uni - I think we can all guess that from your post already! What do you hate about uni? The actual place, the course, the people, what? If its the particular uni, you could go somewhere else - you may have to go back a year though depending on the course. If it's the course, change it! Plenty of people do this after first year.
One thing uni is very good for is making you grow up and be responsible for yourself - part of this process is learning to stick with things that maybe you don't particularly enjoy. Life is full of things we don't enjoy, but some of them need to be done! If you quit now, get a job, and you hate the job, will you just chuck that in as well?!