I don’t have much better to offer than what Pep already suggested. But yes, definitely don’t do new lessons before the reviews are done. Also:
1°) Take your time: they stacked over a couple of months, don’t think you can or have to make disappear within a couple of hours.
2°) Trust yourself: You won’t remember everything but you’ll remember more than you give yourself credit for.
3°) Don’t get discouraged: You came back and checked how bad the damage was. That was the hardest part. You’re back with even more motivation and energy than before. Now just tackle those reviews one by one, little by little.
4°) Look af cute/funny Japanese pictures or anything that might remind you of why you like Japan and Japanese culture so much and why you want to learn Japanese so badly.
5°) Before you know it you’ll be back onto the Wanikani train and ready for new adventures!
(Optional 6: Make yourself a leaderboard (if you haven’t one already) and add me. I’ve already added you It helps me stay motivated, so it might be the same for you!)