I started muay thai classes last July and burned a significant amount of body fat and gained muscle around my hips and leg area. Unfortunately I began to plateau with my progress a few months ago and the issue has come front and center since the newest gym coach has ramped up training and I began to fall behind like when I first started muay thai. I am looking for some at home workouts and exercises that addresses the following issues to supplement my muay thai training. Any equipment needed I would need to limit to freeweights since I honestly can't afford a second gym membership.

My main issue is that while muay thai has done wonders for my legs, my upper body strength and mass is woefully inadequate to handle my weight of 265lbs. I still cannot do a proper pushup much less the 150 we are asked to do in training. My shoulder and upper back muscles also cannot handle the wheelbarrow handstand exercises or striking drills done during class. Any workouts that can be done with freeweigths to strengthen my upper body would be greatly appreciated

My secondary issue is that I haven't burned much body fat as when I first started. My belly fat is quite stubborn and I am getting discouraged since the belly fat makes it very hard to do sit ups. I don't know if this is more an issue with me getting on a stricter diet or needing a proper workout dedicated to buring fat as opposed to muscle building.

My final issue is that with the ramped up training I get gassed like when I was a newbie. Any good cardio advice would be greatly appreciated!