What you're describing is pretty much how CBT works. The therapist would ascertain your 'safety' behaviours (staying up late as you feel it prevents you getting sick) and get you to do gentle experiments to test out whether or not there's any substance behind it (maybe going to bed an hour earlier) and the idea is that the first few times you'd be anxious but the more you do it and push through the anxiety, the less anxious you become as you re-programme your brain to see that the safety behaviour is actually futile and not keeping you safe at all, only feeding your phobia
Have you looked into having CBT? I think it might work quite well for you....