@hannahGE_ Give him some time to adjust ... as you said he talked to you on Thursday (it's not months) perhaps he just needs to unwind a bit. I doubt it that he's ignoring you, but I'm going to say be warned, if you keep badgering a person, it becomes annoying. Someone did that to me and kept telling the person to stop, but individual did not. So in the long run, friendship deteriorated. (I already have an annoying autistic brother I have to deal with everyday, adding more drives me nuts) *Smirks*
Now if something bad has happened, perhaps you should contact someone who knows him and ask how he's doing. I did that for some former friends.
Hope everything goes well. Take care!