I was in my apartment with my old roommate.
That sounds normal. Did you enjoy being in that apartment with that roomate?
Yes, we had a good time.
Most of the time when you have a roommate you're going to spend some time with them, so it's good that you got along. You should continue hanging out together to improve your relationship.
I don't like my new roommate. I hate it.
But you liked your old roommate right? Maybe eventually you'll like your new roommate just as much as them. You'll never know unless you give them a chance.