I genuinely and urgently advise you to hire a coach ASAP and book multiple sessions to get a crash course in casing.

This is honestly the only way I see you having a reasonable shot at succeeding here.

If not going this route, you need to get at least a few live cases under your belt, learn the top 5 case types/frameworks, and get to a table stakes level with fit and fast math. Skip firm/industry stuff.

Learn top 5 case types - 3 hours

Do live cases  - 10-12 hours

Practice fast math - 2 hours

Prepare fit - 3-5 hours

Hello,

I also highly advise quickly getting in touch with a coach or experienced professional who can quickly pinpoint the areas you need to work on, so that you can make your preparation as targeted as possible. I would focus preparation on: 

1) Refreshing your memory of best-in-class case frameworks and techniques 

2) Doing live cases (this should be the bulk of your prep) 

3) More targeted practice on any problem areas of the case (this is where feedback you get is super crucial) 

4) Preparing (and practicing!) stories for the fit interview

I generally agree with Ian in the amount of time you'd need on each section, I would just also throw in any other case specifics that you feel you need extra work on alongside with the quick math.

Best of luck, and feel free to reach out if you'd like any help - I'm available for coaching sessions over the next few days