Pain is the demon that has haunted mankind for all time, and over the years, we have done many things to try and relieve it. But there are only a certain amount of things that actually work. Number one for extreme pain, especially temporary pain, is the pain killers, such as codeine, morphine, heroin, oxycodone, etc.
If you are in a lot of pain, and simply cannot see a doctor or find a drug dealer, go to the chemist and buy some pills with paracetamol and codiene, crush up the pills into a powder and mix in a glass of water. The paracetamol will gradually sink to the bottom, but not the codeine.
About 100 mg of codiene or even a whole box will be enough to make you feel a little better, but this is not a long term solution. Things like sex, or chocolate can provide a quick endorphin release, but these too are temporary.
The Buddhists believed that meditation could help to relieve pain, through finding the inner void, and losing consciousness slightly while still being conscious. In fact, Zen Buddhism is solely focused on relieving pain, through control of the mind.
An adrenaline rush can work great. But if you don’t want to take drugs, do crazy things, or become a Buddhist, the best way to relieve pain is by making your brain work hard, thinking about complicated things, to take your mind off it.
I suggest reading my articles on where the universe came from, and so on, as the questions brought up about eternity will give you a lot to think about, and I always found I got relief from my pain, by thinking about the cycles of endless time, and reincarnation.
If that doesn’t work, you could try acupuncture, or other alternative therapies. Bare in mind, the more you focus on it, the worse it may seem. I just drink a little to kill my pain. It doesn’t work great.