I'm glad you're feeling better.
The thing that rebuilds self-esteem is really getting away from depression. The longer you can stay out of a deep depression the more self-esteem you have. Also, doing things that make you feel you have accomplished something really helps this. It doesn't have to be big things. Like finishing your chores, getting showered and dressed every day, or completing small projects you'd left undone are all things that help you start to rebuild.
Bigger self-esteem issues, though, can be hard. For example, I was bullied througout my childhood and part of that was being told I'm ugly. Getting passed that has been close to impossible. Even my husband who tells me that I'm not ugly doesn't help, and I think he's crazy to think it. That goes all the way to the core of myself which just shows how bad bullying can effect you.