If you are allowed to drive a car, you can fly in the UK on a PPL. See CAA website for online application form. The conditions for self assessment are in the application form.
If you are a student, ask your AME for advice on your position.
I failed my Class 2 in November 2008. I got it back in February 2009. I'm EASA Class 2 at present.
Exercise is important.
Best wishes.
Edited to add: still not on any medication.
Last edited by Maoraigh1; 15th Mar 2017 at 23:00.
Reason: Addition