Blocked ear is vile and makes you and those around you feel miserable. I get it every few years.
It will not go away by itself so it needs sorting.
I'm aware I'm a pain while I've got it.
So no - you are NOT being unreasonable.
If you want him to change his behaviour, telling him to won't work. He needs to think and feel differently first. Some assertiveness techniques may help!
Start with 'I understand that … ' and empathise with his symptoms and its effects.
Effects include:
Loss of hearing = Communication much more difficult for both of you
It hurts - pressure on the eardrum can be very painful
It feels like a dull heavy weight pulling your head over = your balance can be affected
Tinnitus, fizzing, rumbling, buzzing, hissing noises can drive you mad and stop you sleeping, which makes you feel worse and behave worse around others
Some people suffer these permanently of course, because of different health conditions - but with blocked ear, all these problems are temporary IF he gets it sorted out. It will not go away by itself.
Then 'however…' with the effects this and his mood is having on you both.
Him failing to get it sorted is affecting both his quality of life and yours and is also affecting your relationship.
And finally 'therefore … ' with what he needs to do next to get better.
DIY - Boots ear drops do help with softening but really better as prevention than cure. I found the DIY kit no use at all, probably because I was terrified of causing damage.
I managed to get an appointment with my GP nurse who uses an electric water syringing machine (not the giant steampunk brass syringe they used to use by hand any more). No problem whatsoever getting her to do it, so it's not yet abandoned as a treatment.
Boots Hearingcare and Specsavers do offer it if he cannot get it done at your surgery.
If he gets it sorted he will be in a better state of mind and health to campaign and complain once he feels better and can concentrate.
Sticking to a calm controlled broken record approach will help you keep your sanity as you deal with a frightened bloke whose world is closing in because this tiny insignificant thing, a plug of removable earwax, is not being dealt with.
So you know - the effect is usually instantaneous and fantastic. But sometimes even though the nurse can see it's all gone, if there's cleansing water trapped in there it can be several days before it feels clear. That will go by itself.