Omg kaplods-walking on a broken foot for a year, yikes!! I hope things have healed OK for you.
I completely agree with Demosthenes!! Exercise with caution. When I had plantar fasciitis my doctor didn't tell me not to walk for exercise and as a result of that i now have developed posterior tibial tendon dysfunction and arthritis at 28 years old. I would swim or recumbent bike only if I were you. The condition I developed from overuse while trying to get healthy is permanent and painful. Take care of yourself.

Thank you, all, for your great advice! I switched to 30 minutes on the treadmill in the morning, and 30 minutes of recumbent bike in the evening. What a difference! I may lose a bit more slowly that way, but if it means I won't give up then it's worth it. Thanks, again!