How to survive a trip on an UNEXPECTED budget?

Hey sooo.... I have a trip planned with my boyfriend next week (Las Vegas, 4 nights). Flights, hotel, tickets for the 2 events we're attending to are all sorted out.

I had a budget for this Vegas trip but, unfortunately I had a bunch of unforeseen expenses this past month. My car breaking down multiple times, close friends/family birthdays, life in general. This trip was pretty unexpected too, the idea of going came to us about a month ago, almost two.

I can only spend about 400-500 dollars MAX (I know, that amount might be crazy for Vegas) and I'm stressing out about if that's even enough, or if I can make it.

My boyfriend and I don't like clubs so that's a win, we also don't plan on going on casinos. We don't drink. So that's like, the only good thing that could help me ease my mind about the spending. But I've heard the restaurants/activities are high priced, so I'm here, asking as my last resort, is it even possible to afford 4 nights on that budget? Any advice?

Also, I'm not from the US, that's why I'm so lost about this.