Brain fog

So I’ve stopped smoking on December 23 2024 and I have an endless amount of brain fog that doesn’t seem to be going away. I tried sleeping in and going to the gym (up to 3hours a day) it still seems to be there, so any other things I should try? To clarify I’ve been smoking on and off since I was 13(now 30), the longest I’ve been off was 4 months from September 2022 to December 2022 and it was never this bad. I want to start studying and get my life back but this annoying brain fog is making it hard.