I pretty much have to restart it. It seems the DLC wasn't made for every game style but instead for people with high sneaking skills and high melee/unarmed skills
By level 20 (the recommended level for doing the DLC) you should be proficient in at least three skills and decent in a couple of others. The only character type that would
really struggle in Dead Money would be a low Endurance Barter, Lockpick, and Science based character with little to nothing in the way of sneak or any combat skills.
Energy Weapons characters have the holorifle (arguably the best EW in the game).
Guns characters have the police pistol and the Automatic Rifle.
Melee and Unarmed have several options for weapons.
Explosives characters can get quite a few mines as well as gas bombs.