I Am 49 Years Old, I Take Androgel 1.62 And

i am 49 years old, I take androgel 1.62 and simvastatin only. I am 6' 2" about 245. I was running on a treadmill up until recently. it has never been easy but lately it is very uncomfortable. short of breath, legs tire quickly and mild chest discomfort. I believe most of it is my weight but not sure any suggestions. I am starting diet very soon. Low carb tends to work best for me. im just concerned its not all weight.