Everyone drinks on Freshers week but I feel awful when I do!

I’m coming up to freshers week at university and everyone drinks to have a good time. Honestly I’m very shy and reserved and drinking makes me confident and I can’t have a good time without it, especially in nightclubs and stuff. The thing is I get super bad acid reflux and go too feel sick after it start to wear off and I genuinely can’t stomach it, I’m on pills too that make me sleepy when I drink and go depressed too! It’s expensive too, but I dunno how to talk to people without it