1st off, something that caused me a lot of strife, for the longest time I just, didn't realize I got all the keys. So I was just running around like a headless chicken and getting widdled away, that might be happening to you to.
2nd, if that fails stock up on healing and status ailment recovery. You can use your inventory when navigating the map, so any time anything happens to you, heal up to max right after
3rd, run away as much as you can. Get gear that makes it eaiser to run away, respec to be able to run away, go the whole nine yards. You should not be fighting the hell hounds unless you have to.
Hope that helps