I'm playing through my first time solo, and I'm having a hard time. I've been trying to tackle all the side missions so that the story missions would be easier, but the enemies (although not the quest level) are keeping up with me. I'm lvl 30 now, and I'm always evenly matched or even overmatched in terms of lvl.
I'm dying all the time, on side and story missions. Even when I went back to do the Statuesque mission, which says it's lvl 24, all of the enemies are scaled. It's really making for a bad play experience.
I used a siren and I loved it, phaselock saved my life many times. If you are having trouble respec your skills to the middle tree, its health regeneration is huge.
Also make sure you have a good SMG. Maybe use a few golden keys, donate money to moxxi until she gives you one, or maybe even farm a boss for one. Without good guns you will be screwed, things did get fairly tough for me in the 30-40 range
XBL gamertag: eingram21 Life is a maybe. Death is for sure. Sin is the cause. Christ is the cure.