I met a guy who's interested in me but he is polyamorous. I'm not one to judge but I used to be poly and I've learned it's just not for me. He told me monogamy isn't natural for humans. It's centered on jealousy and envy or whatever. I HATE when people want to give me unsolicited input on how i choose to love. The problem is I am extremely Jealous. So I can't say I'm being healthy I guess. The thought of being in another polyamorous relationship makes me...I'll just say triggered. 
Another problem is I'm becoming attached bc he's showing me such kind affection. I've already tried to push him away and he said it'll take more than that too get rid of him. Says I need people. But it's just pain feeling for anyone. My mind sends intrusive thoughts into my head of him having sex with others or whatever. I don't know what to do bc I want to be friends with him but it's so painful I just wana run away. And I don't want to put him through me. Idk what to do I feel destroyed. This is why I don't date or try to get to know people heavily bc this happens EVERY SINGLE TIME  WITHOUT FAIL.
Please if anyone has read this far I could use your input. I've never gotten help with these feelings I just internalize but I can't anymore