Really tired all the time, is it allergies?

Hey, quick question, I’m pretty much allergic to everything in the air, my nose is clogged up 24/7. My throat and sinuses hurt and I use 50 tissues every day, but that’s manageable, however I also suffer from pretty bad brain fog and sleep 11h every nights only to wake up absolutely miserable and go through my day like I just pulled an all-nighter. I suspect it’s all because of my allergies (I hope so), can anyone else relate/confirm? Would it be because of the inflammation itself or caused by a possible sleep apnea?

Btw I do take 2nd generation antihistamines (all brands pretty much useless for me btw) but those symptoms where there before I started.

And I had blood tests done, I’m apparently in perfect shape (yippee)