I (23 M) am not sure how to deal with money with my BF (21M)

Hey! I recently started dating someone, and it is both of our first relationships. We have only been dating for 5 months. We both go to the same college in NY, and we recently decided to make a 3-day road trip in Early September.

The financial discussions for our upcoming trip have been a bit awkward, and we sorta decided that I will be footing the bill for the hotel, while he would cover gas and food. I felt like this was a bit unfair, as the cost of the hotel is probably ~3x what gas/food would cost us. I had brought this up and I noticed it was a bit of a trigger for him, and it was clear he wasn't too keen on having the discussion. I don't think this comes from malice, but more so that money discussions are always awkward, and this is both of our first relationships.

I had offered to split it so that he pays a quarter of the hotel charge, and he sort of reluctantly said yes, but mentioned he doesn't have the money right now, so I didn't really push further.

Both of us have different perspectives on money - he is a lot more frivolous than me in spending, while I'm pretty frugal. Even though we're both in university, I have more disposable income than him (mostly because of my frugality).

I'm worried that I will resent him during and after the trip because of this, and I know I need to bring it up to him, but I don't know how I should approach it. I do really want to go on the trip, and I realize that I may be too "cheap" and should let things go. At the same time, I'm feeling more and more resentful whenever he mentions how he spent money buying (non-essential) new clothes or books. I've been bottling it up for a bit since he's going through a bit of a rough patch, but the date of the trip is approaching and I can't keep my mind off things.

To clarify, my questions are:

1. How do I bring it up to him? I'm worried if it feels like too much like an ultimatum, we'd have to cancel the trip.

2. Should I just "suck it up"? I know in relationships things aren't always equal. I would like to think if the roles were reversed he would do the same, but I'm not sure if he would.

I can not emphasize how much I like him. My post may have made this sound like a toxic relationship but it is anything but. It's just one small part of an otherwise amazing relationship.