It’s not really a single player game. Coop is very important. You can use cheatengine to modify your character, but it’s unclear if this will result in your account being banned.

Seriously, though, give it a try. If you’re getting beat up by a boss you really can call in help and most of the time a team of three can take down the boss in a few tries. It’s a very different game experience. It’s not for everyone. It’s a little bit like getting used to an unfamiliar exotic food dish - It takes some adjusting but once you’re used to it you can appreciate new flavors you haven’t found elsewhere.