Have to start slow, work your way up. Several years ago I got up to around 230 at 5'9", enough was enough. I started by walking on the treadmill, then walking with an incline, then jogging, and finally running.
It took some time, but I went from walking to running 6 min miles and was able to run 5+ miles easily. Also went from 230 to 160 very lean. You can do it, just have to commit.