That's right, you are who you are and you shouldn't change for anyone. She has changed though and is no longer the person you fell in love with. She is being out of order towards you, threatening to finish with you when you stick up for yourself, it's not on and personally, i wouldn't put up with it. It seems that the women you have been involved with don't know how to appreciate a guy like you, at first it's great, they love the way you put them first and treat them with respect and all the rest of it but after a while they start to take it for granted. Maybe you need a woman who is ready to be with someone like you, and in my opionion it's usually someone a little older who is tired of being treated like dirt by men.