There's basically two ways polyamory goes down:

1: You learn a lot about yourself and unpack all the stuff you've buried over a lifetime, figure out what you want, and are forever changed for the better. Maybe this means you decide poly isn't for you. This is how it went down for me.

2: You double down on all your insecurities, ruin everything, and blame polyamory for it. Most of the negative stories you hear come from this. All polyamory does is amplify what's already inside. It's like getting superpowers. A jackass with laser vision was already a jackass without it.