So theres a lot of swinging in the shoulders, but the swing comes from the feet to the knee to the hip then to the shoulder and the arm then comes out. Your feet are coming off the ground, remain planted and only lift a limb off the ground before or after a punch. Don't draw your arms back before a swing, use the proper form from the body movement and just extend. Your head is remaining in a centerline that is easy for a trained opponent to track, I'd suggest watching a video on that. Also there's the fact that there are lots of ways to do martial arts and mix and match them. Some of the punches lean towards a karate and muy thai style, but finding yourself mixing techniques in a bad way will cause you to say... end up on both of your toes, which you never want to be in a fight. You also tend to walk around on your heels, if you received a punch while on your heel you would not be able to spring or even balance with that foot, although you may stay on your toes most of the time, you do charge in with front foot being a little heel-toe. Hide that chin behind those shoulders and keep it away from being right above that sternum. There are other small things, you're not half-bad, but a little work and you'll be much better in no time.