Sorry to hear that you had to get this surgery.
Healthy eating, enough exercise, enough sleep, and vigilent attention to your meds and FPG numbers are all things I think a doctor will emphasize (check with a doctor - I'm not one).
There is a company that offers therapy that involves a sleeve in a rigid boot. Your leg goes in the sleeve, the sleeve goes in the boot, and an air pressure unit attaches to the sleeve. The air valving is set up so that the sleeve can expand every heartbeat. So your heart beats, your arteries get blood into the leg, and then the sleeve squashes the blood out the arteries. IIRC the therapeutic effect is considerable. Lessens ulcers, neuropathic pain, and amputations.
It kind of is closing the barn door after the cows got out (or, forgive me, the little piggies), but this may be something that you want to search out with your doctor and discuss whether this will help you avoid further amputations, and also avoiding ulcers and infections.
I just saw a youtube video of a young, very pretty gal, who had one foot amputated. She didn't give the root cause, but said that after years of the foot not allowing her to live, and not ever not feeling pain, she was really glad that she'd had the amputation. It allowed her to get on with her life.
Ideally though, it would be good to have the remaining parts of the foot to be healthy. You may wish to check out:
Since 1993, American Medical Equipment (AME) has been recognized as a leading provider of medical products and clinical services for patients from hospital to home.
www.amemedbeds.com
Long-Boot, Valve Assembly and Heart Monitor Many people with diabetes are at risk of developing wounds on their feet that just won't heal Circulator
www.diabetesincontrol.com
Good luck.