Have you ever found it difficult to return to a big effort of yours?
I have found it's a mistake just to jump back into it. You won't make satisfying progress. Instead, try having a session before the session.
This is a priming session to re-absorb it back into your brain.
You dust off old questions, reorganize ideas, and plan next actions.
Then sleep on it and allow your subconscious to work on it while you sleep.
The next day, not only will you be itching to go, you will make satisfying progress.
It's as Mary Poppins always said,
Well begun is half done.
(Word has it she was a big Aristotle fan ;)