Miscarriage

I had a miscarriage last year but I’m unsure as to why, it was at 12 weeks. I think it might’ve been stress because at that time I was with a really toxic/abusive partner and was balling my eyes out picking my clothes etc up off the road everyday. But I wasn’t told by the doctor what happened they just said it’s heart stopped beating.

I’m now 5w5d with my current partner who is literally the nicest man I’ve met in my life 😩😩 but i’m just so scared that I’m gonna miscarry again because I don’t know for sure what happened to the last one..

How can I stop overthinking and always worrying that something bass going to happen?? I can’t help it no matter how much I try to stop myself 😭