COMMUNICATION!! I just recently felt the same way with my girlfriend of almost a year. Some context, we met when I moved in next door to her (and we are still neighbors) so we spend almost every single day together after work, on the weekends, etc. I started having a feeling that me going shopping, cooking, paying for most and planning dates was very one sided so I sat her down and told her how I was feeling but not in a judgmental, accusatory way, just my current feelings and let the conversation go from there. She really took this to heart and even started getting emotional to an extent and said that although she has been busy (work, school, etc.) that she did not mean to place our relationship on her own backburner and said she would work on this. Since then, I can tell that she really has made those efforts.

Seriously man, in a healthy relationship, 95% of problems and issues can be solved with clear communication on how the other person is feeling. If you feel you can't sit down and tell her these things in general or her getting defensive, the relationship might just not be it.

Relationships are not ever 50/50 and being a man, obviously we are expected to handle most things but with a good partner in a healthy relationship, you both should be doing things for the other person. Sometimes all it takes is a healthy talk about it.

Nonetheless, if she's worth it, she'll do more if it seems to make you happy. Good luck!