AITA for mentioning my sister's miscarriage during a fight?

I know the title sounds horrible, but hear me out.

My (31F) sister (26) had a miscarriage this summer. It was her first pregnancy. It was a blighted ovum miscarriage; a very early miscarriage where an egg never grows into an embryo. She called me in a panic when she first suspected it was happening. I dropped everything I was doing and drove over to her house in the next city over. I was ready to take her wherever she wanted - whatever she needed/wanted to do, I was ready to do it. She made an appointment with her doctor for the next day, and I stayed with her until her husband came home. Over the following weeks, I was there whenever she didn't want to be along. I gave her as much support and guidance as I could - as I have my entire adult life. We are/were very close, and I was generally happy to play the role of supportive big sister.

Meanwhile, I've had my own health problems. In the past year, I've been diagnosed with uterine fibroids, depression, and (finally) fibromyalgia. Fibromyalgia is no fun, and often takes a long time to get diagnosed. I was always exhausted, my muscles all over my body were constantly achy, and on bad days I would have muscle spasms that would lock up my neck, and leave other areas of my body feeling deeply bruised. Physical activity would leave my limbs feeling very heavy, and unnaturally sore for days. I fell into depression. I finally received a diagnosis in September, and was given a prescription (the only prescription that I am on). I felt so much relief that I found a doctor who listened to me.

I texted my mom and sister the good news via group text. Mom was happy for me. Sister, on the other had, went off the deep end. Here is a direct quote:

"Getting into a regular workout routine would show you that you don't have fibromyalgia. You absolutely won't hear that exercise would make you better, because HA, that's too simple! Have fun being yet another American who is doped up on a million medications for the rest of your life. Congratulations, you just became one of them. It's just the beginning. Have fun."

I was blindsided, and I said that I was completely supportive of he when she had her miscarriage, and asked why she was being so hateful. She lost it, saying that I was being spiteful and how dare I use her miscarriage against her. Which of course, I wasn't doing, that would be a horrendous thing to do - I was pointing out the disparity between how I cared for her during her health problems and how she was shitting all over me about mine. She has since cut all contact with me, and then our mom when she took my side. It has been 2 months, and we're as good as dead to her. We found out this week that she's pregnant again, and when I reached out and said I was happy for her, she was FURIOUS that I knew and told me never to contact her again.

I don't think I was an asshole, neither does my mom. My boyfriend kind of thinks I was. Should I have never brought up the miscarriage in any context? AITA?

ETA: we both stopped talking after the fight, but she didn’t tell me not to contact her until I reached out to congratulate her on the pregnancy.

Edit 2: a few things I’ve seen people mention repeatedly. A lot of people think there’s more to the story that isn’t being said. Yes and no. As I’ve dealt with these symptoms over the years, she would always tell me my muscles hurt because I’m not active enough (she would always make it sound like I’m a sedentary person, to the best of my ability I’m not), and if I told her that I hurt worse after going to the gym, it’s just because I wasn’t doing it right. So the content of her attack wasn’t necessarily new to me. It was the fact that she felt the need to be so cruel and superior form the jump when I found a doctor that listened to me. The medication I’m on is an antidepressant.

Thanks to everyone for the input, and for all the support from fellow invisible illness sufferers. I guess I feel better about the situation, but in my opinion this is a game where everybody loses.