Low ferritin, DR says it’s normal range

So I recently got my ferritin tested due to having so many symptoms (my previous post goes over all of them). My ferritin came back at 14. I know that’s a deficiency because optimal range is 90-100. Anything under 50 will have you symptomatic. My doctor reviewed it and said it’s in normal range and to continue doing what I’ve been doing.

I’m wanting to get some iron supplements, but I don’t know what dosage I should be getting based on my levels. My hemoglobin was on the low end of normal so i’m not fully anemic yet.

Are there any recommendations? Thanks