Hi and welcome
Although I don't quite understand all of what you are saying e.g. the negative stories. It sounds as if you seem to be going through a jealously crisis. This is my own term for what seems to hit most of us on a polyamorous path at some point. Usually sooner rather than later.
For me the pain was so bad that I didn't even recognize it as jealousy, just pure agony. It came in waves and each wave was significantly less painful than the first.
You'll find lots of support here, infact I kinda look on this whole forum as being my mentor. But if you want someone one on one feel free to message me.
Initially anyway it sounds to me as if this could be quite a healthy thing for your relationship. Polyamory forces you to learn how to communicate with your partner and from your post it seems that this is where you need to start.