when I started university I contacted the disability services and as part of the service they should be able to provide you an appropriate room (e.g. own bathroom, self catered as needed), if there are none immediately available there are usually drop outs in the first few weeks and empty rooms become available which you could be top of the list for...
if you could use this as an opportunity to overcome your OCD habits that would be the best solution, but you don't want to end up in a situation where you can't eat or the stress is preventing you from engaging properly with university life