Go to Andromrda on St. Mark's. I always liked Mikel ( I think that's how he spelled his name). There was a clothing store, same side of the street, around the corner from the pizza shop that has become a Ray's. I don't remember what it was called, and I do not know if it is still there. It was across the street and around the corner from the pizza place, same side of the street as Andromeda, and you had to walk down some steps to enter the store. There was a piercer there I liked even better than Mikel. I think his name is Jessie. You know him by the implants in his forearm. Those two are the best I've had/observed in the city. The latter is somewhatanti-social, but his work is good. Bear in mind I moved out of NYC some time ago.
I had my nipples pierced. It hurt more than anything else I ever got pierced. It hurt more than my tattoo, as well. But, the procedure was the same as for any other piercing I ever had. Breathe through it. If you're pain averse, there is no type of body modification that is for you. Just accept the body you were given. Want ink? It hurts. Want holes? Scars? Discs? Implants? Lipo? Bigger muscles? There is pain on the path to all of these things. Piercing can hurt for seconds, or days. You can either deal with that, or you can't.