So I have two p/t jobs. In one I'm generally fine with my immediate colleagues and the job is ok. I'm in a senior-ish position.

In the other job, I'm more junior but I love the actual work. However, I am so so so ridiculously anxious around my colleagues. As soon as I arrive at work I go straight to my office and basically hide there all day except when I need to interact with the clients/give presentations etc.. I'll happily give a presentation to 150 people, but am too anxious to spend 5 minutes with a colleague. It's ridiculous.

My colleagues are lovely and have made an effort with me. (I've been there a year, newer than most). I appear very outgoing and I doubt they'd think I was anxious. I think they think I'm being rude by not making an effort back, going for coffee etc... but thinking like this makes me more and more anxious.

Today we had an event thing and I was terrified all day and thinking my colleagues must hate me. I wanted to disappear most of the day.

Why am I like this and how can I change? It's driving me insane ...