Forum:Broken Game/ Oh My Papa Help

So I was trying to beat oh my papa and was trying to kill papa khan without failing the mission but it was not working. No matter what I tried (stealth boys, melee weapons, closing all doors, etc etc) it never worked. At somepoint I quickloaded and found papa khan DEAD but it wouldnt let me fail the mission. I had no idea what to do so I just resurrected him and reset the quest. That seems to have screwed me even more as now the quest will not progress past my giving regis the ledger again. And if THAT is the case there is no way for me to complete the game as I need to do this in order to finish for the republic 2. And of course the game autosaved at somepoint when I left a room so there is no viable old save to use.

Is there anything else I can do to fix this? Please help.