Women, Is it all of them? Options

[Bigmeanbulldog55]

I'm upset with my girlfriend right now. I've been with her for 4 years now, and she still doesn't understand my passion for cars. You can all read what I've bought for my car in my info. It isn't much. But for some reason she thinks I buy stuff for it all the time. I was telling her I was thinking about bidding on a header online for my car and she got really mad at me. She said, "you don't even need a header, why are you wasting your money?" I just had a birthday, and I felt I should be aloud to maybe buy myself something for a birthday/chirstmas present. I've talked to everyone else in my life, friends and grandpa and mother. They all say, "it's your money, and if that's what you want to spend it on it's okay." I told my girlfriend that all those people said that, but it didn't matter really, because it doesn't matter what anyone else said she is the most important person in my life I can't do something unless she says it's okay. I can't stand her being mad at me. I told her I felt like she's controllling sometimes because she gets mad at me if I don't do exactly what she wants. She got mad at me and told me to spend my money on whatever I wanted and stop caring about what she thought, and it was irritating what I was doing. It feels like no matter what I do, she's mad at me and I can't make her happy. I love her. How do I get her to understand me, and except me?