EBF baby has a sickness bug-engorgement help

[tutuloved]

Really hoping Mumsnet can help.
So I have a 4.5 month old ebf baby who has had a sickness and diarrhoea bug since Friday evening
Firstly, I looked online and it seemed to suggest nothing in the way of keeping baby hydrated other than keeping offering the breast often? Is this right? I'm really worried about him although he seems alert but he's taking hardly any breast milk and what he is taking he's procjectile vomiting back up.
Secondly, I am sooo engorged it's unreal because he's hardly drinking I sobbed my way through the night as I couldn't lie on either side with the pain. I don't own a pump or a bottle so this morning I googled how to hand express into a bowl and that seemed to help a bit, was that the right thing to do? I also got loads more out by hand expressing in the shower, was that ok to do?
Basically, I'm looking for advice on how to handle it all in the best way.
Thanks in advance

Keep offering him milk and expressing off milk in the shower is good too. If he is alert that is great and sleeping More is normal as well. But keep offering the boobs as breastmilk counts as a watery fluid and is excellent for such bugs.
Here's hoping you don't succumb to the illness too. 😷

Poor little thing. When my DD had gastrointeritis and was still bfed I remember giving rehydration sachets in a bottle. Like yours, any milk was coming straight up. Lots of sympathy, it was not a fun week. Maybe pop to the pharmacy for advice?

Thanks Isadora I hope I don't too. We've got another two small children as well and I'm panicking they will get it too.
I will keep offering the boob and see how he goes (the washing machine has been on constantly) sigh.
Hope he perks up soon poor little man.
Thanks also to Esme. I can't pop to a pharmacy until tomorrow Esmè but I will if he continues my mom suggested diorolyte? But I read online only formula babies need this? Not sure if that's correct or not?

Yes diorolyte was what I gave DD. I went to the GP and they suggested it.