Severe Hair Loss In Bulk, Hair Coming Out From The Roots, No Split Ends. How Can Restore My Bulk Hair?

Dear Sir, I am a female, age 33. I earlier had very lovely (great texture, very long and jet black) and healthy hair. But since past 3 years I have been losing hair continuously and in bulk. (Been through emotional trauma and stress , change in city, change in water - very hard now, also intermittently used Sauna at the gym, although not anymore!) Now I do not what exactly is the reason for my hairloss , but I am badly struggling with it. Also, my hair comes off from the root itself, it doesn t break, I do not have split ends. Interestingly, my hair grows in length real quick, but the bulk I can easily say has come down to 25% of my original bulk. By the way, I do have new hair growing, I can easily spot inch long hair growing from the scalp , but sadly, I am losing that as well. Wonder what s wrong? Also, what can I do to control hair loss and restore my hair bulk? Any help is much appreciated. Many thanks, already! Regards!