I recommend that you start taking raspberry ketones, you can get them at Walmart. I've had asthma my entire live and I gained quite a bit of weight, I've always worked out but cardio was a challenge for me. Once I stared taking them I dropped nearly 40 pounds withing 2 months, aslong as you drink a lot of water, take them when it says to, and just try to exercise they work pretty well. I wouldn't think about gaining muscle until you get your basic running schedule down, it'd be great if you could somehow work in possibly 2.5 miles a day at your weigh, even in an hour on a treadmil, or just a hike. Hope this helps.