Everyone starts at the beginning - EVERYONE. When I first started exercising 20 years ago, walking a couple miles pushing a baby stroller was a huge accomplishment. Walking the two mile loop I started on felt like it took forever and I was super tired when I got back, but I continued to do it. Strolling became walking, walking became shuffling and eventually that turned into running. I still remember the first day I ran my entire loop. I was on top of the world. Just stick with it. It doesn't matter how slow you start out, or how short of a distance you go, just go. It will get easier, and the day you reach your goal you will feel on top of a mountain.