aww, you poor kitten.
You can use prep H, and there is tucks wipes, but if you are desperate, you can use oragel. Gross, yes, but since its safe to use in your mouth for tooth pain, its ok to use on your fanny for other pain.
Sitz baths really help. like taking a warm bath just to soak your sore backside. If its burning from the pain of the stomach acid coming out, you can use maalox liquid or mylanta liquid. Since it kills stomach acid in your tummy, it will really cut the burn on your heinie.
Barriers help too, like Desitin creme, or A&D ointment.
If you are in that much pain, you may have thrombosed or clotted off one of your hemmorhoids. That can be VERY painful! Its best to have it checked out. If that is the case, they will have to open it to pull the clot out. it feels dramatically better once its over.
Rocking chairs will help you move the gas along, and heating pads will help it to disperse.
Hang in there.