This is how I feel today.

vapid (vap·id): / VAP id /
adjective

(1) lacking force, interest, or liveliness; without spirit; dull; tedious
(2) lacking strength, sharpness, or flavor; insipid; flat; without or having lost life

[From Latin vapidus meaning “insipid, flat-tasting.”]

Usage: I nearly fell asleep in the middle of his vapid speech.