Gf has extremely sensitive nipples

My current GF (27F) has far more sensitive nipples than I am used to. I haven’t had a ton of partners in the past but so far they have all liked their nipples getting manipulated to a degree (kissing/sucking/gently pinching/stroking). New girl I can’t even cup her in a hand without her being in pain. Is there anything that can be done? It seems okay if I do it over a shirt/bra so would pasties be completely crazy? How would I suggest that/bring up the subject in general? She’s gorgeous but I have accidentally hurt her a couple times by running my hand over them and I’ve felt terrible about it.