a problem with scratching me

I lost Elfie as a kitten when a dog picked him up and shook him. I ran at the dog, and it dropped the kitten. However, I didn't see him again until he showed up as a feral cat-almost two years later to the date. The two other mature feral cats blinded him in one eye. Also, he is Feline Leukemia positive. I have fixed up a bedroom for him which is large enough to give him a good bit of room.

The problem is that I cannot trim his nails and that when he is showing affection or playing, he scratches me every time.
He is friendly and cuddley otherwise. Would a pet groomer be able to trim his nails? I have tried and made a little progress on his right paw. Now he is wise to the trick and is not going to let me do the left paw. What can I do? This is putting a strain on
our relationship.