Career Change Possibilities

I currently teach orchestra at a charter school with mostly (90%+) free or reduced lunch Title 1 and title 8 students.I work with almost 300 students and provide their first and probably only opportunity to play a musical instrument. I LOVE what I do and I love my students! However, I am able to make ends meet because of the child support that mostly pays for my mortgage. 2 of my 5 children are graduating in the next 2 years and once they do I will need an additional 10K ,salary to maintain my current expenses. (that does NOT account for cost of living increases). I am blessed and have sufficient for my needs right now, but I see into the future that my school will not be offering me a raise commensurate with my loss of income; a school is NOT a business in which you get rewarded for the value you add. The salaries are dependent upon a fixed amount of money from tax payers. Sooooooo,
I know that I need to transition into a new career. But I LOVE WHAT I AM DOING…..
I have several options and one can even include coaching. However, everytime I think about who I want to help, I recognize that market does not have money to pay me. For example, If I coached LDS women who are recovering from divorce and re-entering the workforce, they are NOT going to be a group with money to drop on their own needs. Most of them don’t take care of their own needs in the first place so that’s how they end up penniless, divorced and supporting a family.
I also can’t coach musicians. They also don’t have money for self-development.
I can always go back to school and enter the tech field as an engineer. But, how will that make me feel, leaving my work changing the world through music for these minority students I work with? Very selfish.
How do I find a career that is as fulfilling spiritually as what I am doing right now and actually make enough money to save for retirement and future health care needs?