How do I keep my kitten from being so clingy?

I just got a new kitten. I'm not sure how old he is but I'm guessing he is about 6-7 weeks old. I found him a a pet store and felt bad for him cause he was so small and was kinda skinny. He looked to young to be sold in a pet store. He was the smallest in the group, but he could of just been the runt. I love him to death, but he is driving me crazy.....he ALWAYS has to be on my neck/face.....and when I mean always I mean always!! When he isnt on my face he crys and crys and trys climbing his way up to my face! It's sooooo annoying! He is REALLY bad when its time to go to bed, but when I try putting him in his own bed he crys and crys all night long!! I dont want him in the bed till I can get him to his vet appointment in a few days because he has diaherra (sp) and keeps stepping into it in the litter box and track everywhere! On the floor, me the bed ugh its so frustrating. How can I help him become comfortable not being under me 24/7 and using his own bed at night.....at least until we get the poop thing fixed....and even then I don't really want him trying to smother me in my sleep....but by my chest, stomach, feet is fine.