Struggling To Workout Muscle

The bigger I get, the harder it is to exercise and move around! First I try doing pull-ups with a chin up bar placed inside the door frame. Unsurprisingly I can barely hold my own weight off of the ground, let alone pull myself up! The physical activity makes me sweaty, so I remove my sports bra while leaving on my blue thong. After about 5 minutes of multiple pull-up attempts, I give up and try a different exercise. Next I get down on the floor and prepare to do sit-ups. I find that I have NO ab muscles to help me out! But by using momentum, I manage to actually sit up a few times! Push-ups are my last attempt at exercising. I struggle to hold my weight and proper push-ups are out of the question! After giving up on working out, I play with my fat belly as I sit on the floor in defeat! ,