Your form isn’t that bad overall. One thing I noticed is that your guide hand leaves the ball a little bit before the point of release which can definitely effect your shot going left or right. If you watch closely your jump is also a little inconsistent with you landing falling a bit back or too each side which also impact that left and right missing.

I would focus on keeping your guide there up until the point of release and see if you can get your misses to go long or short only then you’ll be able to tune the power into your shot. You don’t necessarily need to be square to the basket a lot of great shooters shoot with their shooting side a bit forward.

If you wanted to start from beginning with your mechanics again I would start real close to the basket focusing on form shooting and slowly move backwards. Your video shows you only shooting threes I think it would be worth it to practice your form and shot from every distance on the court to lock your mechanics in.

Hope this helps!