How did you deal seeing him again

so I posted about how my ex-boyfriend cheated on me at Christmas time. now I have to see him tmrw night for my friend group Christmas party.

and I have no idea how to handle it. I bought a new outfit and tmrw will get my hair done before the party. mainly to make myself feel better and to put on a front that I'm ok. I haven't spoken to him since Christmas and have blocked him on most everything since.

most of the group knows exactly what happened and I have asked some select friends to just keep an eye on me. but still I'm terrified of seeing him again.

how have you gotten through seeing your ex again after the break up? the party is at my house (live with some of my friends) and I don't want to spend the night hiding in my room.