A couple of thoughts. Can you walk to work, or do you have too much stuff to carry? You seem to have time between appointments, so maybe you can use that time to "commute", rather than sit around.
And about those meds you're on... have you had them re-evaluated since you started? They can affect weight, metabolism, etc.
I like the idea of a stationary/recumbent bike (you can read and watch tv while you cycle), some step tapes without the step (more interesting choreography, possibly better music), and maybe throw in some strength training.
Is your son active? When he's with you, maybe you can do outdoors stuff together. Sometimes just having a partner is the motivation you need!
Good luck