Online application is a waste of time, all it does it registers your interest then tell you to go to an AFCO, so either way you'll end up there eventually.
The AFCO is only going to tell you to make sure you know what your GP has said, so might as well start there. He's the one who's written the notes on your condition[s] that are going to affect your application, go talk to them and see what they've said.
However, like has been said numerous times, you have received medication for an illness that is a bar to entry in your recent history, so I wouldn't hold your breath*.
*Pun not intended