Welcome to the FitDay forums!
If you get your eating habits under control, you'll be amazed at how fast the weight will fall off. When I started in May it was all I could do to walk 50 ft. w/o a rest now I do a 20 min. mile pretty easily. Due to your health issues it sounds like you should concentrate on losing some weight before doing anything strenuous.
There are some great threads in the Women Only subforum, and you are welcome to join us in the "Unisex 100 lbs. to lose" thread in the Weight Loss Tips subforum, if you like.
47 M 5'8"
May 4, 2010...... 440? lbs. (Start FitDay Size 60 Jeans)
June 19, 2010.... 393 lbs. (First Weigh-in)
June 19, 2011.... 229 lbs. (164 lbs. gone in one year :-)
Current Weight... 185 lbs. (Size 36 Jeans)
Next Goal 169 lbs. (07/04/12)
Ultimate Goal 165 lbs. (12/31/12)
The best exercises for weight loss are Fork Putdowns and Table Pushaways.