Chrohns / IBD / Colitis during Pregnancy help

Hey all. Sorry for the broad title, recently I've had a flare up of chronic diarrhoea, three weeks straight and I'm 21 weeks pregnant. I think it's linked to SSRIs I was prescribed (sertraline) I'm reaching out to anyone who has had to manage a chronic bowel condition during pregnancy and had a flare up? It's likely mine is something called microscopic colitis which is known to be linked to sertraline, which can only be diagnosed via colonoscopy. I've had samples taken and anything viral / alternative ruled out and have had no previous conditions likely to be linked. I'm so worried about baby, as it has been hard to keep food and fluids in for any length of time and it's only when I found a better over the counter supplement rather than loperamide, that it eased off and baby's movements got stronger and increased in frequency. I can't take these forever as they're not recommended during pregnancy, I'm getting nowhere with my GP and I'm concerned that most pro biotic / pre biotic foods aren't pregnancy safe either as it's fermented / aged, otherwise id try my upmost to adapt my diet and try to treat from home. Can anyone give advice? I know it's a really niche problem but I'm just scared baby will suffer from not getting enough nutrients and the things I'm taking to cope short term will effect her. Thanks ❤️