I don't think I'm depressed but i just don't feel anything any more and prefer to be on my own?

I've had depressing before and I know for certain I'm not depressed. I feel like if I accomplish something I would have in the past got a high from and felt good but now I Just feel nothing, I don't feel hurt or upset or happy or elated. I used to always needs friends with me to do anything and now I love doing things on my own, going to town on my own, walking on my own etc. I've never been like this my whole life and I feel like I'm the opposite of what I used to be. I used to be shy but still liked meeting new people now I'm not shy meeting new people but I hate making the effort and don't care if they like me or not. I'm in university and I feel very anti social like I don't particularly want to make friends and I sleep most of the day.