Seems like several of us are from the windy city. I am in the Oak Park area.
I started at almost 300 8 months ago and it is slow going because I have physical limitations also. I am about you height. Actually just a tad shorter than you.
I started very slow on exercise. I couldnt walk a 1/4 of a block, so I know how you feel. Perhaps you can start slowly by walking one flight of stairs ( at your own pace). I found if you do something, ANYTHING, it is better than nothing.
I understand your reliance on the Lord is not a cop-out. I am also a believer. But as the saying goes.. God helps those who help themselves. So perhaps asking Him for the strength to start doing a little movement may be the best start.
As Almeeker said, the 100+ thread is one of the best around for encouragement and nudging too
Hope to see you there.. and good luck on your journey!