Dyed Hair and Increased Shedding?

[ExpectoPatronum]

As some of you may know, I recently took the plunge back into the world of dyed hair. I dyed my hair once a very dark brown, and then decided to go black for the heck of it. I waited a week between each dye job and babied my hair between. Both dyes I used were ammonia-free and I left them on the recommended time. I did use two different brands, though. The first one was Garnier Olia and the other was Revlon Colorsilk.

I just got done washing my hair and the hair ball at the end was scary. I've also been noticing more and more hair in my Tangle Teezer and just every where in general. I worked so hard to get my thickness back after a stress shed and a massive shed from trying CO. I'm really disappointed that I'm once again losing thickness.

Is it possible that I'm allergic to one of the dyes? I didn't notice any itching or redness while I applied it so I don't know. I also dyed my hair a lot as a teen and never had problems, though I know that's not always going to stay true into adulthood. (I'm allergic to a lot more things now, sadly). Could it be something unrelated and this is just a coincidence? I've been to the doctors a couple times this semester for stomach issues, but nothing came up as wrong with me, so I don't have any underlying health issues. I also haven't changed my hair routine either :/

I'm just really bummed that my hair is thinning out again after I worked so hard at getting its thickness back. I really don't want it to be the dye as I love having darker hair :(

ETA: I'm also experiencing itching. Could this be a PPD allergy?

[Rosetta]

I've never experienced increased shedding from dyes. It could just be a coincidence, but the combined itching does somewhat point to allergy/reaction to the dye... Do you have any dye at home you could maybe test for PPD allergy, in the way they tell in the instructions? i.e. leaving it on skin for a while; that way you could confirm if you do indeeed get a reaction to it. (Though as to those instructions, I always feel *anyone* would get an averse reaction if they left such a substance on skin for 24-48 hours... :?) I'm sorry I don't have any other advice!