Pain--countable or uncountable

The notion of pain is a royal pain in the neck (literally), and it is a real pain trying to figure out whether my pain is countable or uncountable.  So I came across my own writing such as Phenomena.  Da mals I was careless with "pain"; today, I feel the pain--in all capacities--when having to go back to edit my own writing.

The question of the day: my pain-countable or uncountable?

I went through almost all dictionary definitions I could find online on the sensation called physical pain; yet, despite of all efforts, and after the aches and pains resurrected for working too hard and too long, I still can't quite figure out the principle behind the usages given by these dictionaries, and I have no idea what the point is for them dictionaries to simply indicate in one setting that a word is "uncountable and countable."  Can you be even less specific, please?  

At some point, I thought... OK, based on the examples provided by these dictionaries, the word "pain" can be treated as countable if it comes in bouts... like it shots, shots, shots, and throbs, throbs, throbs...  Yet, the example provided by Dictionary.com got me all confused again with the example of "a back pain."  For someone like me with chronic pain, a back pain--like it happens and disappears immediately kind of back pain?  (Can I have that pain instead, please?) 8-O

Then, I went back to them discussion forums I found online and decided to subscribe to the following explanation (http://forum.wordreference.com/showthread.php?t=1925818):

The slightest shift causes excruciating pain - it causes pain as a generalised concept.
The slightest shift causes an excruciating pain - it causes a specific sensation of pain which is locatable in time and space.

Already in pain, don't need more pain on pain, and don't wanna know more pain... speaking of no pain, no gain. 8-O 8-X lol sigh



Merriam-Webster Learner's Dictionary: the physical feeling caused by disease, injury, or something that hurts the body

[noncount]▪ The medication may upset your stomach but if you experience acute abdominal pain call your doctor. ▪ I've had chronic back pain since the accident. ▪ It was obvious that she was in pain. [=feeling pain] 

[count] ▪ I feel a dull/sharp pain if I touch the bruise.

Cambridge dictionaries online: a bad or unpleasant physical feeling, often caused by injury or illness, that you want to stop, or an emotional feeling of this type:

• [U] Your whole perspective on life changes when you’re in pain.
• [C] He was admitted to the hospital with chest pains.

Oxford dictionary:
physical suffering or discomfort caused by illness or injury

• she’s in great pain
• those who suffer from back pain
• chest pains

Longman Dictionary of Contemporary English: [uncountable and countable] the feeling you have when part of your body hurts

• The pain in her jaw had come back.
• I had a nasty pain in my leg.
• Greg was in a lot of pain.
• If you suffer from back pain, consult your doctor before attempting this exercise.
• The patient complained of severe chest pains.
• She felt a sharp pain in her stomach
• Morphine is used to relieve pain.
• a few minor aches and pains

Macmillan Dictionary: [COUNTABLE/UNCOUNTABLE] a feeling that you have in apart of your body when you are hurt or ill

• chest/stomach pains
• Harry has been enduring considerable back pain for a number of years.
• pain in: I'm having terrible pains in my chest.
• ease/relieve pain: The fresh air had done nothing to ease the pain Kelly felt in her head.
• cause (someone) pain: An old injury was causing him intense pain.
• in pain: He heard Leo scream in pain.
• be in pain: I don't think she's in any pain.
• a sharp pain (=a sudden strong pain): It was a sharp pain, on his left side, below his ribs.

Dictionary.com
1. physical suffering or distress, as due to injury, illness, etc.
2. a distressing sensation in a particular part of the body: a back pain.

Other sources:
http://www.perfectyourenglish.com/usage/pain-ache.htm
http://forum.wordreference.com/showthread.php?t=1925818
http://forum.wordreference.com/showthread.php?t=2254875