I’m against dropping levels, unless you know that you have forgotten absolutely every single item in that level. I recently came back from an unplanned break to 700+ reviews and have been chipping away for a month while also adding daily lessons and now am down to 163 reviews.
As everyone else has said, no new lessons since it has been so long for you.
I recommend the [Userscript] Reorder Buttons and to do items in ascending order.
I would also recommend using >> BISHBASHBOSH << to get extra practice, especially on the items you fail in your reviews. NB: only use this immediately after your reviews, otherwise you’ll interfere with the SRS.
You are going to fail a lot of items which will be coming back as Apprentice and Guru, so keep an eye on those numbers and adjust your review batch size accordingly so you don’t get overwhelmed.
Best of luck! You can do this! Great to have you back in the community 