My Period is constantly irregular

My period has always been really irregular. Especially in times where I am in high stress situations, I end up finding it hard to maintain my weight. And I think with the combination of the high cortisol and low weight I have found it really difficult to try and keep healthy. I constantly feel nauseous and have such a sensitive stomach. I eat healthy but I feel like I can’t keep it in (sorry for the over sharing). I’ve seen my GP about it and they did tests and said it was just stress related and to try take time to relax. I do and I regularly exercise but I still struggle. Has anyone been in similar situations or has any tips ?

It would really be appreciated