Hi, I can understand your anxiety. You are dwelling on these issues and they are snowballing down hill.
If you met this guy one time and you don't hear from him again, that is not to say you have done anything wrong. You are a great person and lots of people say they will see you again and never call. This is the nature of dating. Be good to you, don't depend on some one you just met to do it for you.
Now your room mate.............IMHO, sending you email at work is uncalled for and only upsetting you. Try to sit down and talk to her, set your boundaries. She should not be sending you personal emails at work unless it is very important and to just email you to slam you is way out of line.
Look for a new room mate sweetie, yours is not very considerate.
Try to stay in the moment. If your at work, just take care of work and try to keep the away from work issues from taking over your thinking. Sound fair? It works, I know I have to do that very thing.
Hugs to you.