Good luck dude! I'm 22 and starting right now! I wish I did it at 19 tbh. I hope you can do it so by my age you don't regret that you didn't!
Welcome to the challenge!, this will not be easy and it will take all the willpower you have and it will tempt you and try to trick you in every single corner of your brain, stay vigilant and fight this with a clear mindset because a moment of a guard down means a lifetime of slavery of your mind