endo flare hit me an hour before the club... how do you bail without making it weird

so we had a date set with a couple weve been chatting w for like 3 weeks. drove an hour to manchester, got the hotel, was actually feeling cute for once. then bam... endo flare from hell hit me getting dressed. like the kind where i couldnt stand up straight, sweating, the whole bit. my partner was so kind about it but i could see he was disappointed too which made me feel worse. we ended up texting them from the hotel saying i was unwell and they were lovely about it but... idk i feel like i ruined everything. how do u guys handle the night-of cancel when its a chronic thing and not just "oh i caught a bug". like how much do u say... do u disclose endo upfront or just keep it vague forever