My body rejected Zoloft second time around - has anyone else experienced this?

I took sertraline (zoloft) for six years before slowly tapering off with no issues. However, a couple of very stressful life events - including illness and long hospitalisation of my mother amongst other things - caused me a relapse in my anxiety and I was struggling to cope.

I thought I could just ‘hop back on’ the Zoloft. After all, I hadn’t been off it very long at all. How wrong I was!!

It made me progressively more and more ill with unbearable physical anxiety symptoms to the point where I could no longer function at all and eventually became effectively bedridden. Because it had worked for me before I persevered long past the point I should have, believing ‘it’ll get better by 8/9 weeks’ because it had worked before. Well… it didn’t and after nine and a half weeks of enduring hell I had to give up and switched to an SNRI. The SNRI is a much stronger ‘second line’ drug and less pregnancy friendly than sertraline should I get pregnant. So that in itself is frustrating.

I don’t understand what happened to me. I’ve never heard of it happening to anyone else. Has anyone else experienced this? Is there a medical explanation for it?? If I had any idea that this could happen I never would have come off in the first place. I feel angry at myself for causing it, but also feel like I never could have predicted this would happen as it’s not something I’ve ever heard of or come across before. It feels so unfair that something that has worked for me before would cause such suffering the second time around. Especially since I know other people who have been on and off sertraline multiple times with no such issues. The whole experience has really scared me and made me very wary of medication in a way I wasn’t before.

Does anyone have any ideas/explanation what happened to me!? I just want to be able to make sense of it…