Thank you for your concern...Respectfully- unless it's budgeting reasons I don't see why you are doing all the work with your health conditions you described.
Many reasons, budget is top of the list. I was raised to do everything you can yourself and keep pinching that penny (depression parents).
Mostly pride, hate others doing what I can do. Dislike the work others have done (only let others do tires and alignment), keeps me moving and active, I like to do it and I've been doing it all my life (I did hate those Cat, Detroit and Cummins oil changes though!). Every time I do it I wonder how long I can. Someday I'll have to submit.
Thanks again...