Excessive hair loss

For the last year my hair has become extremely dry & I’ve been losing 2 handfuls of hair every time I touch my hair.. I can’t brush it- so I opt to combing it with conditioner in it in the shower, I also have been conditioning everyday & shampooing 1 time a week but nothing is working. I also have been taking prenatal vitamins for 3 months & got a thyroid test done (hypo & hyper & cancer runs in the family on both sides) but my TSH levels came back normal.. I’m so conflicted! I don’t know what products to use or what to do anymore.. I thought it was stress, but I’ve been the happiest ever. Also, even though I’m losing a bunch of hair I haven’t had balled spots yet but I did lose all my natural curls. My hair became straight & very thin... I haven’t dyed my hair since last summer and I also don’t use heat anymore for the last couple months.. any advice on what to do?