Why doesn't my male cat want anything to do with me no mote?

I've recently had my 1 yr old male cat neutered and it's been little over a week Sinse hes operation, whilst it's made him a calmer cat (he was a little crazy before but very affectionate often coming to me for cuddles) but now he doesn't want anything to do with me. He'll cone home when called and meow at me for food but if I try to go near him he'll run away and if I try to touch him he scratches or bites at my hand. Can anyone tell me why he's acting like this?