What are some good jobs that you can work on your own and not be around people?

I am nice and can get along with others, honest, reliable, trustworthy, but I get stressed out too easily being around people and I lose focus a lot and get too nervous. I'm getting help through all these anxiety issues, but I want to know what are some decent, good paying jobs where you don't work with any customers, maybe like a couple of co workers at the most, or by yourself. I've worked as a vet assistant/kennel attendant for over 10 years at the same place, but I'm tired of it, and need a decent living, stable income. I know there are jobs out there to work on your own, just need ideas? Right now I just work after hours on weekends taking care of the in hospital animals, and i used to work during the week but can't take working with clients that much. I need full time work too. I'm more productive when I work by myself, and I don't get anxious.