What Causes Obesity While On Birth Control Pills?

Question : I feel like my regular doctor is not listening to me. I'm 37 female not on any medication except birth control
My issues are when I go hiking within the first 3-7 minutes I'm complete out of breath huffing and puffing. I'm not gasping for air but am breathing like I just ran 5 miles. I wear a heart rate monitor and when I start the hike I'm around 100-110 heart rate. After the first 3-7 minutes I'm already at 155. If I keep going it goes to around 170 very quickly that's when I start really feeling it and must stop for a few minutes then continue. I'm moving very slowly obese and elderly people are passing me with ease. Also during my hikes or walks. My fingers swell up to the point I can't bend them. I am very hydrated all I drink now is water ( I used to be addicted to soda) no tea no coffee no soda just water, sometimes light lemonade. Me and my husband did a mud run obstacle course race. I struggled big time he even had to carry me at one point because I couldn't get my heart rate down to feel I could continue. During that race I injured my shoulder. This injury has me out of the gym with weights so I'll I can do is cardio and I can't seem to get my stainimum up no matter what I do. I don't get out of breath when I lift weights but any movement that I used to do jumping or stepping up would cause heart rate to increase and breathlessness. I can only do 7 jumping jacks before I have to stop. After walking up 1 flight of stairs I can't speak until I regain my breath. All my dr hears is you hike you go to gym your health. I saw a different dr he recommended a stress test. I guess it was normal they never really discussed the results with me. But they did have me laying on the table for a long time after the test was over. I believe my heart rate never went back down to resting and for me resting is somewhere in the 90's they had me taking deep breaths but that keep raising my rate finally they said close enough your good. I just don't feel right I know what I feel is not normal and something must be wrong.