I need advice on how to handle this situation
I made the mistake of dating someone from my work and the truth is that we broke up for various reasons 3 months ago and just at that time I went to work to another office in the UK while he stayed in the US and we haven't seen or spoken to each other.
The problem is that I have to go back to the office to work with him in January, we have many projects together and we are in the same team and we didn’t finished in the best terms
How do you recommend handling this situation or giving me some tips? I honestly believe that I haven't healed him completely and I'm afraid of what I will feel when I see him.
Hold your head high (fake it till you make it if you still aren't feeling great), do your job, and do your best to avoid office politics. Chances are he's buddied up with quite a few people from the office during your time away. Scope the situation first and give it time to see what "alliances" this guy has made.
No long water cooler chats, no hanging out and talking after work with people. Be as "absent" as you can be and do your work and go home. If you hear rumors, ignore ignore ignore. If there are rumors and they get too bad, go to HR.
But I would say your best bet is to act dignified and don't hang around people longer than you need to.