If he was hitting his injury to feel stronger from the pain, why couldn't he push this girl away?
Send him to /fit/
He was pounding on the wound he suffered from Chewbacca's bowcaster bolt. By hitting himself in the wound, Kylo was accentuating the pain and using the pain to focus himself; using the adrenalin/endorphin rush to make himself stronger; feeding off of the anger caused by the pain and bringing the Dark Side to bear more strongly against his opponents.
It is similar to the "runner's high" achieved by long-distance runners. The pain in their limbs sends adrenalin and endorphins coursing through their systems and they achieve a "second wind". This is a physical, not psychological, phenomenon due to adrenalin and endorphins. It's also similar to the "high" that masochists get during sadomasochistic acts: It feels good to them and helps them achieve orgasm.
Serious question: Why does all modern movie banter need to be Will Farrell Anchorman style banter? Why does it never sound like something the character would say but rather just the same stuff for everyone? Laziness?
>Rey and Finn enter the Millenium Falcon and go to the gunner and pilot seats
>They both say "I can do this" out loud to themselves
It's just unnecessary and dumb, real people don't do that.
Didn't he get shot further towards his back though? He hits the area at the bottom of one side of his ribs.
I figured he was losing sensation from blood loss and cold, and was trying to basically keep his body going
There's literally no reason why Rey wouldn't trade BB8 for rations. Yeah it's a cool little robot friend but she's clearly malnourished and would probably sell her pet dog for 2 months worth of decent food.