A bit of background:
I started fainting at 11 years old, diagnosed with vasovagal syndrome at 17, non responsive to meds so pacemaker implanted when I was 21.

Pacemaker didn't work and I still faint. I'm now 26 and a few weeks back I started to get double vision but we put that down to head trauma from collapsing. I saw a neurologist yesterday and he's a bit stumped, he wanted to do an MRI but can't because of the pacer so I'm getting a CT scheduled.

I work in optics and I've done a bit of research into what could cause double vision that shifts between eyes and gets worse as the day goes on, Myasthenia gravis seems to fit. Then I started to think more and realised that even with the pacemaker I always did sports but now I cant climb a hill without getting breathless, my knees and ankles hurt a lot for days after I've been out and I've been getting headaches and neck pains but I've put them down to the effects of the double vision.

I have allergies so I know my immune system is a bit mental, how do I bring this up with my doctor without sounding like a hypochondriac? I can't face being fobbed off for years like they did with my syncope.