Hi ZW. Congrats on posting some video and for having what seems to be a comfortable and coordinated stroke. I see two things that immediately came to mind.
Thing 1: you look up when you swim. Try to keep the crown of your head pointed to the far wall and your eyes down. This will help with balance and less drag.
Thing 2: You stroke too early. Like at second 44 your elbow of the stroking arm is at the bottom of your ribcage even before your spearing arm gets completely wet. Hold the spear a bit longer so that you can take advantage of your momentum in the glide, better balance from keeping your arms ahead of your pivot point (lungs) and so when you finally do stroke you have that other arm more fully in a streamline position. Right now you are stroking right into your relatively blunt head/body instead of into a longer arm-out frame.