I had written up a lengthy reply earlier, deleted it and I now I will repost it. Honestly, I see no dichotomy between physical illness and mental illness, but I recognize others have divergent points of view.
I know it's a bit late in the game for you at this point, as you are leaving in less than a month. However, I say this to you as a fellow OCD (hand washing compulsion) to see someone about Cognitive Behavioral Therapy (CBT). It is a very brief course of treatment and it consists of identifying your automatic thoughts/cognitive distortions and providing you with the tools to stop those thoughts.
I am not going to lie, this time of year is a challenge for me. However, what I was able to take away from CBT was the ability to stop those automatic thoughts regarding germs and replace them with rational thoughts. I finally realized getting sick was not a catastrophic event. Honestly, life is 110% better for me now that I am no longer enslaved to intrusive worrisome thoughts about "germs" and the overwhelming compulsion to wash my hands.