I do apologise but I was having a super crap day, I was 
about the whole kitten meeting thing, I think they just want to look at the house. Some of the comments querying meeting the kitten were funny.
I don't think people were wrong to say they'd never heard of it.
In some ways yes inviting someone you don't know is a bit off. I've been sitting in at a house getting work done, I'm not an overly social person, these people were strangers, sometimes it's nice to meet new people and chat. Sometimes with anxiety you have to be in situations you're not 100% with, as yes anxiety is crap, but you can't let it control you.
I say that as someone who has had anxiety most of my life, even being agoraphobic at times. If I stuck to what I was comfy with I'd never have got past the agoraphobia. I wouldn't say many people know I have anxiety as I don't talk about it, but if there's a totally random scenario, you could put money of me having worried about it in my 4 decades on earth.
A prime example I was severely emetophobic too, I didn't drink, I wouldn't eat out, I'd only eat certain foods, if I went to visit family and I learned there'd been a bug or even if their child felt sick I'd bolt out the house. I struggled with my children being sick. Then I got really unwell and realised it's not on the top of anyone's things I love doing list, I'd like to thing I deal with it better now. I wouldn't go on rollercoasters. I hated doing baby clinics for weighing in, as germs.
Sometimes you have to move out of your comfort zone. I think if you'd gone ahead, you'd realise these colleagues are a good judge of character, it wasn't as bad as you thought.