<human>: Can you give me the gist of the text in a nutshell?

My [22M] Japanese girlfriend [22F] of 2 months says things that deeply disturb me. Often times she says things like " what would you do if i said i no longer loved you", and when i react seriously to these things, she says "its a lie" or "I'm just teasing". I have confronted her about this so called "teasing" and she keeps insisting i am "taking her too seriously" or i am "overthinking things".  Threatening breakup was also used once which i have angrily told her never to do again. She also likes to hit me, not hard but she says she enjoys it, me being slightly m and her being s, i don't mind as much but i should write this down as well.

I should also preface this by saying her family is pretty fractured with her father leaving her mother to start a new family when she was young, making her have trust issues. She also has a plethora of mental issues like claustrophobia which i believe to be quite serious, ie cuddling for ling periods if time with her as little spoon would cause "pressure". She also has school and work meaning her free time or personal time is short, often she suffers from stress which i have carefully tried to help with, i think its working... 

I know there is a big culture difference considering she was raised in japan where we currently reside for the time being. 

I am Canadian asian born overseas and emigrated. This is my first serious long term relationship and i have no idea what to do.  Should i continue to just pretend its teasing? She says it helps her relieve some of the built up stress. Need help feels bad :(
<bot>: Japanese GF has trust issues and mental issues from parents, hits me and tells me things at disturb me, threatened break up once, first time relationship lost and need help.