Is it risky to play squash after broken ankle. Is squash good cardio excersise!?

I broke my ankle just over a year ago and i still get pains there! i wonder is there a weakness still even tho the doctors say its healed. I had 1 physio session. I also snapped a tendon or ligament cant remember which. My achilles heal hurts sometimes, just aches. Ive put on almost 50lbs since breaking my leg and am fatter than ever, I weigh over 280lbs now(i am 6'4). I want to start playing squash to burn off some excess flab. I did play before and was good. If i buy and wear an ankle support thing(to wear the first few weeks to hopefully strengthen it up), im not likely to break it again am i?