I had been in the green industry working for other companies for 30 years before starting my own business at 53 five years ago. My forte has been to develop an organic/natural lawn, tree and shrub application business. The physical demands are less compared to landscaping. While your expectations of 40K in the first year are high, the Bridgewater area is ripe for this kind of service. It's something you might consider looking into.
BTW, your not old. you're only getting a little wiser!
The nation that destroys its soil destroys itself.
Franklin D. Roosevelt