The RAF always attracts more high calibre pilot applicants than there are training slots available. Even in years when applications slumped and available slots soared (the 'easy' years).
High quality, high calibre candidates are NEVER guaranteed a place at FTS.
And things are particularly tight at the moment. A glut of trainee pilots in a shrinking air force. Many PPRuNers joined an RAF with 30 fast jet squadrons (Gulf War 1) but we're now looking at the real likelihood of a long term structure of just 12.
The recruiters only need the best of the best.
Virtually everyone they see at OASC will have "the same fierce desire to fly" that you have, if not more so, and (for many) their commitment to the RAF will be longer term, will not have so obviously 'wavered', and will not be 'an issue'.
Of course it will count against you, though it could be argued that your actions showed some maturity, and some realisation of how serious a commitment was required. But you need to do something that will 'remove' the question mark that would now make your application 'stand out' for all the right reasons.
It will also count against you that you are a year older than your contemporaries at Uni, and (stupidly) it may even count against you that you want to go to Uni at all. There seems to be a growing shift towards DE. I only hope that you're going to be reading something that the RAF views as 'relevant'.
In fact, in your situation, UAS service may be an excellent way 'back in'. It may be slightly easier to get onto your UAS, and if you do succeed, you can then use your service to demonstrate your commitment and qualities. Nothing will impress OASC more than a glowing report from your UAS CO.
My 'advise' would be to develop more of an eye for detail, in order to present yourself in the best possible light, and to avoid looking slapdash. ("I was awarded" not "I was award.."