Hi there. Dealing wit tough managers or coworkers can be tough business, and you can't always say what you would to say to those people (if you're interested in keeping the job, of course).

Do you have a counselor or a therapist? They make great sounding boards for stuff like this. If you don't have one, may I suggest obtaining one? It sounds like this issue is really bothering you, and I am sure having a party that is 100% on your side to discuss it with would be a big help. They could help you make a plan of action to handle specific situations as they arise. Does your work have an EAP program you could go through in situations like this? Perhaps they would be the most equipped to help.

Have you tried talking one-on-one with your boss/coworker assertively to let them know how they are making you feel and what actions they are taking that make you feel that way? Perhaps they are simply unaware that they are making it difficult for you to do your job or that they are making you uncomfortable.

Do you have a human resources employee you could speak to about your boss'/coworker's behavior, if it is really inappropriate? Or perhaps that person's boss? I would try to save this as a last resort, after you have tried assertively addressing the problem with your boss/coworker...Sometimes it has been my experience that it only makes things in the office more tense.

As a last note, I think the easiest way to get people more comfortable talking to you in the office is to initiate conversations with them first...

Hope that helps at all.