I constantly think people are angry with me. It can grow and grow in my mind (where it all began anyway) and then I will speak to them, get their friendly facial expressions, and it all melts away.

What I have learned is to force myself to interact with them when I'm starting to think they are angry with me, and to be assertive and ask if they are upset with me. In the event that they are (and usually then look bewildered and tell me they are not at all!), then it can be worked out right away.