I do not really have experience with weight loss, but I just want to give a word of caution:

I think you should try to run, or to cycle, or to tackle any exercise your mind fancies, for the FUN and fitness it brings (and a little for the competitive edge if you're so inclined...), for the satisfaction of being in better shape, but be aware that it may not be the easiest way to lose weight.

Exercising stresses your body and is likely to increase the mass of your muscles before it decreases the amount of body fat you have. It will also require that you keep eating: you can't starve yourself if you're trying to achieve new fitness goals. Surely a nutritionist who knows something about exercise could help you here.

The good news though is that when you do lose weight it will be in a healthy way, and it will most likely stay off if you stick with your exercise routines and attempt to reach new goals.

I'm rooting for you, go for it!! Set the scale aside and enjoy your hard-gained fitness!