Possible gingivitis self-diagnosis

So i have been experiencing a very metallic taste in my tongue since i was 13-14 i'm now 17 and think it might be due to gingivitis .I don't know why , i mean my acid reflux used to be bad and that would sometimes leave an unpleasant taste in my mouth.But i noticed it started disappearing and rarely happens anymore.So i have kind of ruled that out ,I also have chronic nasal drip but that only gives me a bad taste when i try to spit the mucus out of my mouth. Which i have stopped doing for a while and have opted for nasal sprays i either swallow it or spray some nasal mist in my nose during allergy season.And i do go to dental appointments every 6 months but my doctor never diagnosed me with any sort of gum disease.I even asked one of the dental assistance who cleansed my teeth about the taste once, and she said something like "its probably gingivitis maybe you should try flossing more often and it'll go away ".She sounded kind of unprofessional but any way i took her advice and started flossing more but i still get that taste in my tongue and it's so unpleasant and hard to ignore. Again i started having this problem since i was 13-14 now i'm 17 i heard gingivitis can progress into a more severe state called periodontist.And i'm surprised i have not noticed any signs of periodontists yet. I mean my tongue gets a slight whitish color when it gets the metallic taste and the back of my gums are kind of receded so I think i'm 90% sure i may have gingivitis.Even though i don't think it has deteriorated yet.And yes the back of my gums bleed sometimes when i floss and these are symptoms commonly associated with gingivitis.It can't just be post nasal drip or acid reflux. I have braces so i often see an orthodontist who has yet to diagnose me as well,though i'm not sure if orthodontist can diagnose gingivitis.

Again i have been flossing and brushing my teeth better,i tend to skip out on flossing in the morning because i don't have much time but i will definitely try flossing more.but i still brush my teeth and mostly floss at night.My orthodontist has said my teeth are healthy but i don't think so.I wanted ask anyone who's ever had gingivitis or currently has it.do you or did you experience a metallic taste in your mouth ?,does the color of your tongue have a whitish color and did you get diagnosed by a dentist or by yourself ?. And is having a metallic taste a common gingivitis symptom.