Is 50/50 fair when he makes way more?

So we’ve been together 8 months and up front we agreed to split everything 50/50 — rent, groceries, bills, even date nights. seemed fair at the time but now it’s starting to feel off. he makes about 3 times what I do and honestly that gap is growing since he just got another promotion. I’m not struggling exactly but I watch every dollar — I meal prep, drive an old car, no gym, all to keep up my half. meanwhile he takes work trips to Vegas, buys new gear, never blinks at dinners out last week we had a fight — I asked if he’d consider adjusting the split, maybe 60/40 or even covering rent so I could catch up on savings. he said “fair is fair” and that changing the system now feels like a slippery slope. but it doesn’t feel fair to me — it feels like equality isn’t always equity you know? We’re intimate and close, but this money thing is making me pull back a little. like I’m embarrassed to suggest vacations or nice things because I can’t match his budget. am I wrong for wanting it to feel less like a math problem — more like we’re actually in this together