What should I do? I think it's wrong to block him.
Why are you thinking of blocking him?
I'm getting tired of listening to his complaints.
You shouldn't block someone that is not trying to be harmful to you. You should talk to him first about how he is doing. You may understand  why he is complaining so much if you do.
I think this sound like a cry-baby. I'm sick of his shit.
It's wrong to block someone without first giving him a chance to improve. It's best to let him know how you feel instead of being rude to him.