Having a painful platonic love?

You could talk to him. Even if you are very casual, you may eventually be able to progress. Things could go very well, if slow. But that could easy some tension. You could change jobs and avoid him altogether, but I truly believe that would be worse for your depression and wont help you overcome any shyness. That could also leave you with that obnoxious "what if" thought in the back of your mind. And if you leave things the way they are, he is likely to move on and tension and depression will most likely worsen. If I were you I would just try to have a conversation. You could maybe have a gl of wine after work, if that doesn't interfere with your medication. Maybe invite a few other people to help break the ice. The worse case scenario would be that he says no. Either way, some tension will be lessened. Good luck. Be brave!