Life has taken an unexpected turn, and I might have to get into a physical fight soon with a MUCH bigger opponent lol. Can anyone impart their wisdom?

Im studying abroad in Ireland and there is one student here in my relatively small cohort who has recently been a large topic of discussion because of extremely unruly behavior when he got plastered one night. This behavior got him placed on housing probation and as such has scarcely been seen around the building. He was never friendly to me, although Im not really sure why, i guess hes just an asshole, but today he crossed the line. I saw him for maybe the third time since his incident and as he was walking past me he called me a fucking bitch right as he got to the door to leave. For context this guy is a couple inches taller than me and obese, id guess around 250. Now, Im not a very tough guy, but in that moment I was appalled he would say something like that and I wanted to take a shot back, but didn't for the sake of class around a group of friends. After this incident has marinated for a couple hours now, the fire and courage has subsided and now Im having feelings of doubt and cowardice. I can't let it slide if he says something again, I want to fuck him up, but I'm now scared im gonna get the shit kicked out of me. What should I do :p