I need some advice on having a better work ethic at home. Any help?

I have a volunteer job at a bookstore in my town, and my “bosses” think I’m amazing. Like, they’ll be offering me a job the day I turn 14. The rest of the kids are getting jobs that keep them busy in the “employees only” back room, while I get the jobs where people will see me and ask me questions and ask me to help them with something. I’m really happy about that.

My friend is making a movie (The script is 70 pages. This is serious, not just some kid’s summer project.) and he’s asked me to be there as much as I can, because he knows I would be useful to have. I’m really happy that kids my age think I’m good, too.

Then there’s home…I’m always doing something wrong, I’m always standing around, I’m always doing what I shouldn’t. I know why. It’s kind of a vicious cycle. My mom hardly ever tells me I do something right, so I don’t even try at home. Then she tells me what I’m doing wrong, I try even less…..You get the idea.

So my question is…What do I do?