I would probably start off with something that has more support than VFFs when doing box jumps. Don't kill me for posting you need to wear regular shoes but when doing a movement like that where you're not really getting any cushion can't be good for the shins or knees. I wear my VFF's all the itme but not when I lift legs. They killed my feet when doing jumps, squats, etc.
Today is a new day. You will get out of it just what you put into it. If you have made mistakes, there is always another chance for you. And supposing you have tried and failed again and again, you may have a fresh start any moment you choose, for this thing we call 'Failure' is not the falling down, but the staying down.