Wiktionary suggests both “fixing to” and “fitting to” are used synonymously. Fwiw, in Tennessee, I only ever hear “fixing to”. As someone who learned English outside of the southern US, it makes little sense to me also. But what makes even less sense to me is people saying “trying to” to mean “want to”.

Also consider a healthcare career. As a teenager, I wanted to do computer science/engineering, and sometimes I do wish I had stayed on that track. But now, as a nurse, I could get a job in any state in the US by tomorrow. I dare you to try to find a hospital that doesn’t have open nursing positions. Even when the economy goes down, people still get sick. Even if society collapses, the knowledge/skills will be useful.

And if you don’t want to change diapers or deal with blood, there are still options; I’m in psychiatry and rarely have to deal with either.