How can I improve my lot, for side work?

TL;DR - I'm doing desktop support and break/fix stuff to earn extra income, and need more customers. Would like to do as much remote as possible? How do I get more customers?

I have a pretty good paying technical day job already. A couple years ago, I made some poor decisions that got us into some debt. Some necessary, some not... but it's still painful. About $24K of debt, in total.

Since I'm not a programmer at this point, I don't have the higher earning power like programmers do.

I can do sysadmin and break/fix work though. I'm comfortable on any platform, and would much rather be doing Linux/UNIX work, but most of my work is Windows-realted, by virtue of its market share.

My question is... how do you get extra work for stuff like that, when people who have those skills are a dime a dozen? Thus far, I've been doing break/fix work, and troubleshooting desktop issues - to earn some extra money.

I've been charging $75/hr for this work. Should I be charging more? less?

I am working on learning Python, so that I can increase the services I offer to customers, but with a day job and this side work, my efforts are slow going. I know I could earn more as a programmer, but it's going to take some time to get to be able to do it on a paid basis.

I appreciate your help.