Chronic sinusitis alone can cause many of the symptoms you've described......adding allergies to that equation, in my humble and non-medical opinion, explains ALL your symptoms. The puffy, and possibly droopy, eyelid is a common symptom of both sinusitis and allergies. The headaches are a no-brainer, if you'll pardon the pun. A headache caused by a brain tumor drops you to the floor, it does not feel like a "stress" headache.
Can you explain why you would go see an eye doctor and NOT mention all the symptoms you were experiencing? I do not mean to be harsh, but why bother going in the first place if you're not going to be totally honest with the doctor? I DO understand that fear of being told there is something seriously wrong.......it is unbearably frightening. But you absolutely MUST learn that knowing is better than not knowing. I also understand how dfficult that concept is to grasp. I use to think if I didn't know, I wouldn't be scared. But guess what? I finally got it through my thick head that it was the NOT KNOWING that was scaring me more than anything. If you don't know, then all you have are the nightmarish "what if's" haunting you day and night. You have to learn to look at it ratioanlly which is hard. But the fact, the rational fact is...........if you DO have a brain tumor, you want to know so they can fix it.
When I was a little older than you, my hypochondria was focused on lung cancer. I think you can relate to how terrified I was all the time. Back in those days, if you wanted to work in the food industry, you had to have a chest X-ray to get your health card. Well, as you know, a chest X-ray would show that I had lung cancer. (We didn't have the Internet then, but we did have libraries, and I spent enough time in them to KNOW for a fact I had lung cancer!) Like you, I didn't want to find out I was dying.
Well, I didn't have lung cancer then and nearly 50 years later I STILL don't have it and the brain tumor I had hasn't shown up yet either.
Changes in your vision could mean you need glasses. Could mean you're spending too much time in front of your computer or texting on your cell. Needing glasses can cause headaches. Sinus problems can cause head and face pain like tightness in your cheeks (where you have sinuses) and headaches anywhere...........top of your head, back of your head, side of your head, your ENTIRE head.
If I had a medical degree, which I don't, I would, nevertheless, bet that you do NOT have a brain tumor and I forbid you to Google brain tumor anymore! As hypochondriacs, we can find diseases to fit every symptom we think we have and symptoms to fit every disease we read about. And if we can't connect the dots, then it's because we are the first humanoids to have THIS particular type of brain tumor! Logic means nothing to us! We are dying and the Mayo Clinic is not sending a private jet for us.
My parents totally gave up on me and all my diseases. But sadly, in those days, nobody EVER mentioned the word mental illness. You, on the other hand, are extraordinarily lucky to live in an era when seeing a therapist is as common as going to the dentist. There is absolutely no shame any more in having some small bats in our belfrys. You need professional mental health therapy to deal with your hypochondria and anxiety. You need to sit down and discuss this with your parents because it's highly curable and I don't believe you're parents want you to continue to suffer with this. They may just not understand what you're living with. Print out some information on the computer about hypochondria from places like the Mayo Clinic, the Cleveland Clinic, UCLA, Mass General and the American Mental Health Association. I'm sure if they understand that you are suffering from a REAL disorder and not just seeking attention, or whatever they think, I'm sure they will get you the help you need. As a parent myself, I can promise you that we'd sell our souls if it would make our children well and happy again. I would just ask that you don't sort of blow your cool and toss the papers at them and do the teenage "I told you I was messed up" routine. (Sorry if that makes me come off sounding like a stupid adult, I was a teenager once and know the routine and now I'm a less stupid adult) But, this is serious stuff and you're living the best years of your life feeling sick and scared and you really need your parents to help you through this, which is not going to be easy, but with your determination and their support, you can do it. It WILL NOT simply go away. It WILL get worse if left untreated.
You can also go to our forums here that deal with brain tumors. Those folks will be able to give you a great deal of information. There is also a Hypochondria Forum and us..........you found us!
Information is good. A little information is not good. Self-diagnosing is disasterous. Reaching out for help is the best.
Let us know how you're doing, OK?
You're going to be just fine!