Looks like your energy is good.
A few points to ponder;
1)You are a counterpunchers dream opponent with the way you leave your head unprotected.
2)Not many hooks to the head. Might want to work some in there.
3)The constant swinging of the bag tells me that you are push-punching instead of snapping your punches.
A proper snapping punch will cause the heavybag to shake rather than swing wildly.
Push-punching will tire you quickly in a real match, and if you miss with a push-punch, you'll be off balance and wide open for a counter.
Practice throwing more punches from shoulder level, then comong back to guard quickly. Also practice snapping your punches. It'll feel weird at first because you'll have to use less power until you get the hang of it, but when you do, you'll be able to punch harder and throw faster combos without getting as winded.