Might not be eating clean enough

Also running 30 minutes 3x a week will work wonders once your lil gimp ankle gets better

defs gona be looking into running as well as jump rope, i really wana become proficient at jump rope it looks like an amazing skill to have, as for running i know road work is a must but its such a drag lol. Lungs gona be hating me for sure

Seems to be a very difficult task. People gifted in genetics like mike tyson and the real deal Holyfield had muscular builds and still performed well in boxing. A lot of the muscular look depends on your genetics. For boxing you do need excellent cardio. To build muscle, you have to eat a lot and lift. That means you would have to train for both during the day. Then after some time, then you would have to cut. The amount of nutrition that you would need is crazy. I don't think anyone here is qualified to really help with your goal. I think you need someone with much more knowledge and experience. But if you have stamina issues, then I suggest juicing vegetables to get the most nutrition. Fresh carrots and cucumbers always worked for me.