How can I(28M) explain to my GF (22F) that I can’t afford to pay 70% of everything?

We live in a nice place, but I pay the whole rent. She has a job and works hard, but she doesn’t use it on anything major. I also regularly buy her nice things, and it’s taking a huge chunk out of my wallet. Just being honest here.

Thing is, she’s my first gf since I was 19 so I need to make sure this works, I don’t know if I have too many other options even though I work out and am in good shape for 28. But, I no longer have money to do things I personally enjoy. It kind of goes towards her life now. No more shooting range, no more gym membership (have to do it at home now), and I can’t even afford a yearly trip to see old friends now. I told her this and she doesn’t seem to care, what else can I do?