Not being a good boyfriend

I'll try to keep it brief.

I'm just not the best, I don't know how to explain it beyond that.

My girlfriend has asked me to change some things for awhile, a better sleep schedule, moving away people that are just generally not good people, and a myriad of other things that make me just not good for her.

I take these in, and I fully understand her issues and what I need to change but it just keeps happening kind of. I'm not ignoring her and we talk about issues but I'm still not noticing improvement with myself and she keeps having to remind me.

I think part of me feels like I'm going to be this way forever, but I know I want to be different.

Where do I start?