I wasn't hopping for an advice but thank you very much for it and don't worry life doesn't always goes the way you want, but sometimes you gain expirience and try not to make the same mistakes again.Oh...I'm sorry to hear that. I don't think there's any problem with your personality, it's just that it probably didn't match with that girl or situation. Happens all the time ;)
As for her culture and her love for her cousin, well....I don't know the details and I'm guessing that's an obstacle which is hard to overcome. But if you like her, keep being nice to her, talk to her a lot, it's alright to be happy with these interactions even if you won't get together with her. It will be great it she would start to share the same feelings for you. Forcing yourself to forget her will make matters worse. Time will allow you to move on gradually if you have no chance with her.
Well that's about the only words I can give you but hope you feel better about it.
Anyway back to topic.
So what are the chances that MK will have a afterlife chat and Minato might mention Sakura.