What were your inital symptoms?

I know reddit can’t diagnose me with anything nor do I completely believe I have a brain tumor but the thought has resinated with me since the possible thought that it could be one. I have two questions for anyone that could answer them first: What were your inital symptoms/ how were you diagnosed, two do my symptoms sound familiar. For around a year I have taken a deep dive in my health. Since October 2018 I have been nauseated almost everyday even though its minute to my other symptoms now. I started seeing a GI and she said it could be GERD and put me on a pill that did nothing. Starting probably when the nausea felt better even though I still have it, I have been off-balance, clumsy, nausea, vasovagal syncope, constant minor headaches (like I have had one for a month that is just very minor and tends to dip away when I am not really focusing on it), seeing auras in my vision (sort of like eyebleaching but it happens with objects that aren’t even bright), and the most mysterious one is losing all focus in my vision and pretty much spacing out but it happens constantly and I normally have 20/20 vision. Now I am really sorry if I bothered anyone with this post but only being 16 I am really concerned and doctors just blow it off as migraines even though the medicine does nothing.