I'm by no means an expert, but I would suggest that you (if you aren't) spend a lot of time with your kitten. Play with it, talk to it: coo and praise it, spoil it, cuddle it when it wants to be cuddled. Double this amount of attention whenever you and your kitten come home from the vet to reinforce the fact that you aren't as "mean" as the vet who stuck needles into it etc. Maybe going to the vet was a shock for it, and you patiently need to remind it that you're a nice wuvvin hooman with a nice cosy lap.
Some cats won't become lap cats at all though, but still be as loving even if it isn't climbing all over you. One of my kittens occasionally sleeps on my lap but much prefers to snuggle up to my side, neck or armpit instead for a nap or a cuddle. And that is just as cosy and you don't have to grit your teeth when your LAPcat tramples and claws up your tummy
This is my 5 cents, good luck

hope you and your kitten will become best friends again.