Hi Raving,
I rather enjoy giving advice to future aviation mechanics, technicians and even engineers - I see it as part of my job to be a bit upbeat and to get people into what I have always enjoyed.
Personally - I think you really must be Raving!
Your 37 - self-employed, and at such a stage in your life as to be able to dream of something else......
So...You spend the next few years working for far less than a gartrage mechanic and in the eveings you are trying to study to pass 12 -17 modules for a licence to be an aircraft mechanic or technician.
You end up at the wrong side of 40 with little or no experience that most places want.
Stay where you are! you would not like the pay drop.
(Edited for rather poor spellink)