Got invited on a really fun trip but my anxiety is telling me not to go

I got invited on a ski trip with this guy I've been dating and some of his friends. He knows I have anxiety but not to what extent (it can be severe depending on the situation), and he's never seen me anxious or panicky (we've only been seeing eachother a few months and although I've been open in saying I do have anxiety I haven't necessarily wanted to make it super evident yet). The trip is about 6 hours away and as stupid as this is I get really bad anxiety going that far from home and my parents (I'm in college). I get most afraid of getting sick (I'm afraid of throwing up) or getting too worked up from anxiety and making myself sick/miserable. Overall I just worry about something bad happening being that far from home because my parents couldn't quickly get to me if needed.

I told him I'm thinking about it now and I don't want to say "hey I know we're almost 20 but I'm anxious about going that far from home!" Because that sounds absolutely ridiculous and he's a super adventurous guy so I just don't want to be like that.

I don't want to be a downer and really want to just be normal and go on this trip because I know it'd be fun and any normal person would probably be super excited, but my anxiety is telling me not to go and I need to make a decision ASAP.

I don't know what to do.