Are you the breeder?
Since he is only 8 weeks old he should still be with him momma at this point. Have you taken him to the vet and what have they told you?
Puppies should not fall over and shake. When was the last time that he did this and how is he now? If this has just happened you need to get to an ER vet. He is very tiny and when they are little like that you could easily lose him
This is very concerning and want to stress to you that puppies do not fall over and shake--EVER!