I would advise against both resetting (been there, done that, regretted it) and doing as many as 300-500 reviews a day to get caught up. Do now as you mean to go on - if you do massive chunks, they will come back to you in massive chunks. How many reviews were you doing daily before your break? You could add 5-10%, but I wouldn’t do any more than that.
As others have written, no new lessons until reviews at or near 0.
I agree wholeheartedly with konekush regarding the prioritisation script, except for this bit:
No real need to do this; once you are caught up and are afterwards keeping your reviews at 0, it won’t make much of a difference.
(Sorry @konekush - didn’t mean to reply to you, just to the thread in general).
P.S. If you do end up with a lot of leaches, you could use the self-study script on leech mode to get some extra review on just those items.