I was in the same boat (and *mostly* still am), but I found that if you get the shock-set (including the "boost all shock items by 2 each time this fires" weapon), you can beat the game.
But, to do that I had to change my enemy selection strategy. I found that, with melee builds, it doesn't really matter what enemy you choose, but with any other build, it's extremely important. You have to memorize the buildouts for later enemies.
Edit: I now think I've cleared it with every major paradigm except Cannon- Shock, Fire, Melee, Rust, and Pistol.