Have you ever been DOWN?
Ahhhh - haven't we all. Down physically or emotionally or spiritually - or all three at once.
What is the avodah then? We have little taste for davening or learning. Life just flat out ..... [image of person pressing his nostrils closed with his fingers to block out the smell].
The avodah at a time of נפילה is - keep the no-no's. Guard those לא תעשה's. Don't allow yourself to watch shmutz on the assur-net. Stop yourself at all costs from wasting your holy Jewish seed. Keep your mouth closed from speaking lashon hara etc. etc.
The PRIMARY avoda בשעת נפילה is שמירת לא תעשה. [Of course you must still keep all the obligatory mitzvos on a basic level].
When things get better you will start shining again in the מצות עשה category. You'll get back into the learning. Your davening will uplift you and others and you will be a beacon of chesed. But wait till the time is ripe.
[Based on an etza from Rav Yaakov Moshe Charlap ztz"l who yahrtzeit is this week]