Thanks everyone.
He loves his bath and didn't used to have an issue with the shower. It is just since I washed his hair that he had a total meltdown and now won't go near the shower or even let us wet his hair, in any way. The best we manage is if it is raining
I just wish I had never bothered trying to shampoo his hair and left it as it was.
Haven't thought of goggles but I don't think the issue is water in his face - it is that I made him have his hair washed and he doesn't want it done again. I guess he associates shower with the trauma of having your hair washed.
I think, as you said Kebakat, I might have to wait until his hair is itchy or bothers him and let him ask for the shower. Options are limited really unless I frogmarch him in and hold him under the shower. Not really a fan of that though, as that is what has got me into this situation. Guess he is just being wilful but he looking really scruffy too
Don't get me started on a trip to the hairdressers. He really lost the plot them and ended up with half a haircut because they couldn't finish

I think he is very 'hair-sensitive', hopefully he grows out of it soon