Use the divine fighting technique (Way of hunger). Use a Scythe and get lots of temp HP.
Then I use celestial rage power line to gain extra healing. I also have fey foundling. So a cure light wounds spell can heal me for tons of HP. You will drop quickly, but will be right back up on top with minimal healing.
Constitution should be one of the higher stats you have with this build, so your fortitude should be high already. Have the cleric put a death ward spell on you and you should be fine.