Anything to throw harder

First, I want to say sorry in advance for asking for way too much here, but this is very very important to me. All I am asking is anything I can do to throw harder. I will do anything I have to do to gain a good amount of velocity, I just don’t know what to do yet. I have a couple of drills but those aren’t going to increase my velocity a lot. Today I crushed around 51-52 and topped out at 54. I believe I could definetly throw harder on a different day but not by much. I am 12, turning 13 in 5 days, and I am on the shorter side at 4’ 11”. A good birthday gift lol would be to figure out what to do to gain velocity. Thank You.- YouTube

Looking at that video your mechanics are rock solid. Maybe a little more push off on the back leg and slow down the wind up. Other than that velocity will grow as you grow. You’re Young. Be patient. Eat a lot of protein workout and just wait for nature to hit you with a growth spurt. Always work bands and longtoss. Lots of long toss.