Thanks Gill and Sheila.
I understand your point about the purring (I wasn't aware they purred when trying to be happy). I would however say that he seems pretty happy at the moment and he's coming to see us (more below) and his breathing has improved. He's had a very good night.
The big concern right now is his lack of appetite. He's drinking but not eating. I've been to Tesco and have different cat foods/treats and a feshly cooked chicken, plus other options suggested - Primula cheese, Paste, Mackerel, fish, baby food (minus garlic and onion - only 2 tins of about 100!)
Anyway, my post from last night (plus update) that my phone deleted!
I went to bed and shed tears - he's never been away from my side at night apart from about 10-14 days, since we got him aged 2 months - now nearly 18. All of those were when I was away so he's never chosen to not be with me at night, or at least a large part of it.
About 2 hours into my sleep, I heard my flatmates voice at my open bedroom door. I can sleep through bad weather, loud bangs and virtually anything, but her voice usually means something is up!
She whispered that he had made his way upstairs into my room and then I heard him taking the route he always does to get to me. I popped my head up and there was his cheeky little face staring at me. He came and sat/lay by me for a bit before moving across to the other side of the bed and layed with me. Flatmate quickly got him some chicken and he scoffed a couple of thumbtip sized pieces before leaving to have a drink and then go back downstairs. I followed him and then went back to bed when he was settled - within seconds he was back upstairs with me again. He laid with me for about an hour before I drifted off and I awoke 2 hours later and he wasn't with me or downstairs......he'd gone under my bed and was fast asleep. He woke up, came downstairs and I decided to try and sleep some more on the sofa. He slept next to me for a bit, then on a chair next to the sofa and then when I was about to get up to go and get the food, he cuddled right into me on the sofa and wouldn't let me go for 30 mins.
He's improved in so many ways, whether it's because of the tablets or the humidifier or something else. He just won't eat, those 2 chicken pieces aside.
Last night was worth giving him the chance alone. I'll earn the near £300 and any future costs back over time, but i'd never of had last night had he not been given the chance.
He's calm now, a bit slower, but calm. It's just the eating! Come on Moses!