Help! My hair keeps falling out!

Hi there, I'm hoping maybe somebody can help me because I feel like I'm having a mental breakdown. As a bit of backstory I used to get my hair dyed red, I Am Naturally a light brunette. After finding out I was pregnant I realized I was not going to want to keep up with getting my hair done all the time so I went and asked if she can dye it back to is close to my natural color as she could with all the Fade Out. By the time I went I had some pretty sizable roots and was about eight weeks along. I knew she wasn't going to be able to match me exactly but I was hoping she could at least get close enough that my roots were going to drive me crazy for the next 9 months. I started going to this woman after I had my son in April of 2017 and she had been doing a pretty good job on my hair and I have so much of it and it's so thick that it's been hard to find a good hairdresser.

While I was there that day I asked her to match my roots and she says okay she doesn't like show me a color book or anything cuz she's been in the business a while and I figured she knows what she's doing; after she's already started liberally applying color to my head she says something along the lines of oh you like it pretty dark don't you?" this should have been my first clue I just kind of wrote it off. When I first walked in she kind of ambushed me about being pregnant and so it threw me off a lot.

I wasn't really sure what was going on band as my appointment progresses she starts making comments about my mother-in-law and how she thinks it's silly that my husband and I don't want her to be friends with my husband's ex-wife. Theirs was a very tumultuous relationship and ended very badly with her even punching me in the face at one point and my mother-in-law has never supported my husband and I being together even when we were back in high school. Then she starts talking about the ex-wife's new baby and how cute it is and how I should be happy for her or something, I don't know; and that's when she started drying my hair and it is f****** black. Nothing close to my roots or my natural hair color, it is black. Now it has been close to three or four weeks and I've been washing my hair multiple times in a week which I never had to do before, I can go at least a week between washes and now my hair feels greasy and it has been coming out in clumps all the time; I'm shedding more than our Collie does.

Is this just a pregnancy thing or did she completely ruin my hair? What can I do because all I feel like is crying?