Hi Kim_A,
Have you tried Ilex cream? I'm having issues too (two years post take down) and I find that ilex cream is the only cream that really helps.
My butt burn is more like an itching/tingling/annoyance that lasts for about a half hour after I go to the bathroom, so it's not as bad as the initial butt burn I had after surgery, but it's still very upsetting to be so distracted by that part of my body for large parts of the day/night.
Even though ilex cream is just a barrier cream without zinc to help with healing, it seems to really help.
Also, I am surprised that very hot water helps you. My gynecologist told me that very hot water will make the nerves more sensitive and that I should keep my baths to warm water. I still use hot water, but not very hot. I also add epsom salt to the bath, which I feel helps. (Could be psychological. Who knows.)
The thing that makes the most difference for me is when the stool is more formed. Eating Metamucil fiber cookies has helped with that.