My worst pain flares in the past..where sleep was a pot of gold at the end of the rainbow; I would let out my frustration by projecting my pain onto things..or family(not fair to family). I then retreated and "shut-down".. insomnia could last 4-5 days or more, I was not a "very nice lady" to be around. The smallest thing, that on any other day would not even cross my anger radar, would put me into a crying rant.
Sleep heals; keeps balance in one's life...we NEED SLEEP!
Hunger, also something that can set me off...being hungry can make Dew a big drip!!! The pain flares make it difficult for me to eat anything.
There may be a pattern here; the basic essentials to a healthy life; food, water, sleep, sex....being pain-free...causes mood changes. Self preservation kicks in, and it is this natural force that ignites the fight and flight within each of us.

Dew