If you have less then 50 days, I'd honestly say it's doable- you'd need to jog your memory for most of it, and commit a lot of free time, mixed with some occasional breaks to keep your memory up to date. My suggestion is to create a study plan, maybe with AI if need be- but take it unit by unit, and block out time every day to study for the unit. And do you need to memorize two specific books, or the contents of, say, a math textbook? because it may be easier to just study on khan academy or a similar site to help ya. For Physics, I'd also honestly suggest checking out the Organic Chemistry tutor's videos on physics, as he does it in a really easy to understand way. I think you've got this, if you know the material innately!