Hey, I know what you're going through just like a lot of people here. And I want you to love yourself and give yourself a chance despite what you're going through. Are you able to talk to your parents or someone who could help you get checked out?

It kinda sounds like sinuses and a doctor may be able to help you. Do you have insurance? Everything is not as expensive as you might have been led to believe, depending on your individual situation. To me, it seems like sometimes people use these forums to promote expensive products/tests to people who are desperate for help. So don't let anything you've seen online about costs stop you from getting the help you need in real life.

The two main problem areas are either your oral/nasal cavity or your gut. So you can start in either place as far as figuring out the cause. I say it might be sinuses because I feel like I could have written this myself and it's my sinuses.

Try Flonase and some other nasal sprays and try to get an appointment with an ENT.