Spend as much time as possible prepping for interviews and the minimum amount of time you can at your current job. Hope that you don't get fired within the first 6 months and begin actively applying for other roles as soon as possible and when you are ready. The expectations of your current role sound impossible for anyone to maintain. Working hard at your current job will only leave you burnt out. You should put all your energy into interview prep so you can land a job that will not leave you exhausted like this one.