Obv don't listen to this contrarian troll.
Anyone who has had back issues knows you do not want to aggravate the situation.
Keep up the work you've done. The water intake is very helpful and they say cold water actually helps with weight loss. Also see your family doc about your attention deficit condition. A prescription for Adderall or Ritalin will not only make you sharp at the tables you'll drop pounds like a drunken cockney.
I should edit my post with this......walking is probably the best thing you can do for a bad back and still get exercise and
the family will love it as well