It's going to be an issue.
Most experienced pilots, and especially fighter guys (since we can climb or descend 10,000 ft in less than 20 seconds) learn to valsalva without the traditional "nose pinch."
I can do mine by flexing my jaw forward, which works even with an oxygen mask. When travelling on an airliner with a small child, I get them to yawn, chew gum, or laugh...anything that moves the jaw, and therefore (in most people) the eustachian tubes' opening in the throat.
The ability to valsalva is part of every civil and military flight physical that I've ever done. They look in your ear, and ask you to do it.
You may have some scar tissue or other abnormality in a eustachian, and if that is the case, I'm afraid it might be disqualifying.
But I'd get an aeromedical doctor's opinion, not an ENT.