My cats back claws...?

So i have a cat thats almost 20 pounds. he has had trouble loosing weight. He was the runt of the litter and was abandoned very young and i feel like he had some developmental issues. anyways, he is a couple years old now and his claws, mainly the back, are just weird. They are like huge and they have like an extra layer of nail surrounding the normal nail that peals off when i cut them and his cuticles are cracked and sore and i feel so bad for him. I bath him a lot bc hes so chubby that its hard for him to reach certain spots. Im going to take him to the vet to see about getting the back declawed but they were especially bad tonight and i was wondering if anyone had any suggestions on how to sooth them for the time being. I dont know if i should soak them or put something on them, they were pretty sore tho. Thanks!