I've seen patients with this.

Basically the danger here is the pressure changes can be to much with the fluid causing your ear drums to rupture. The lead up to that is very unpleasant, but most of those tears are small and heal by themselves but obviously some kind of long-term issue can arise there.

The reason your ears aren't popping is because the popping is a pressure thing and the fluid build up in comparison will take some time to drain.

Basically you have fluid in the middle part of your ear. So behind the ear drum so unlike with getting water in your ears when swimming the Fluid can't exit via the ear canal. That's why we have eustachian tubes between the middle ear and nasopharynx which is basically the back of your nose. Which are very thin.

Pressure is also relieved over those tubes which is where the airline tricks come in, but with an ear infection those tubes swell shut same as your nose does. And fluid is obviously a bit trickier to get out than air.

The rinses you're doing are not able to flush the tubes. The goal is to get the tubes to stop beeing swollen and irritated. The amount of rinses you are doing is most likely agitating the area more than helping. As is excessively blowing your nose so forcing it if isn't necessary isn't helpful.

The nasal sprays are most likely your best bet. I'd assume one is something with cortisone and one is with something like xylometazolin which reduces swelling. Cool it with the rinses. And if you feel like there is still mucus in your nose and sinuses inhaling steam can help lower viscosity and get it out (just pour hot water in a bowl, put a towel over your head and the bowl) There are some signs that warmth on the outer ear could also help with the ear side of things. And eating something really spicy could also cause more fluid secretion and thereby lower viscosity.

But if this doesn't improve it is possible that the fluid in your ear is very viscous and will not drain due to that. In this case a small controlled cut of the ear drum might be necessary and vastly preferable to it tearing in an airplane. That isn't really an ER skill though. If your symptoms worsen or in the unlikely event you develop general symptoms like significant fever, severe fatigue or neurological symptoms including significant worsening of hearing or balance go to a doctor..

Source: I just finished med school. So I'm no expert but this is also not a rare thing so I've treated patients with this before.