I guess it's about associations. Because you had a panic attack in your room you are now wary of being in there. I would try to make positive associations with your room to help move past the bad. I wouldn't force yourself, but gradually start going back in bit by bit and doing things you enjoy while there, like maybe eating something nice, listening to music and watching TV. You could try doing something that absorbs your attention, like playing games, so you forget about your bad experience while you're there. Basically just make it a nice place to be! Remind yourself there was nothing to worry about. It was just anxiety and everything's fine.