I Have Been On Levothroxine For At Least 10 Years

I have been on Levothroxine for at least 10 years because I have hypo thyroidism...I was taking .075 Mg. I felt like it just was no longer working. I recently went in to a Dr. that is put me Nature Throid made at a compound pharmacy. He started me at 1... 64.8 mg....he just up me to 2 a day. I am just wondering if that is a safe route to go? Also my tongue seems to be coated white...??? Don't know what that is for sure