I haven't walked in a while but when i walked two miles, i felt very winded. how can i start back walking wthout feeling like im having a heart attack?

Walking: I think your body is just trying to tell you to go a little slower. That is, reduce your initial efforts to just half a mile for several weeks, after a few weeks, increase to a mile, after another month or two try a mile and a half, and so on. Unless your health conditions are not adquately uncontrolled, you should be able to build up this way. Your body likes to have time to adapt.

See below: First, see your doctor to make sure you're in good shape to begin exercising (no impending heart attack or weakness of the heart). Second, start slow and be consistent. Start with 1 mile for example and walk on level ground. Then increase the distance or difficulty (e.g. Steepness of hill) every couple days until you get to your goal. Exercise at least 5 days/week. Eventually, you'll get there.