Issues with partner

I am due in two weeks and having massive issues with my partner. I feel like we can overcome them but I’m not feeling comfortable confiding in family or friends about what’s been going on. We are non monogamous but have closed things off since I have been pregnant. I looked through his phone and found some things that weren’t in our boundaries/rules but wouldn’t be considered cheating at all. I’m feeling very alone right now and anxious as hell. He was trying to leave today to go stay somewhere else to get some space and I stopped him which made him so mad. I don’t really know what to do but wait it out until we are both calm and able to communicate rationally. I just feel truly terrible waiting even though I know it will be okay with us eventually. I’m worried about it all and especially if I’m causing any stress for my little boy. Just looking to be heard right now from anyone who may get it a little.