Like you, I married young after dating a while. The guy wasnt perfect, but dating is hard and he was the best thing to come down the pike for me.
I met him when I was 19 and he was 21 and 2 1/2 years later, we married. I had secret poly thoughts (even tho this was the 1970s and we didnt have the concept).
I tried to hide my feelings for others, to "protect" him, but it never worked. He always knew when I had a crush. He had low self esteem and was extremely jealous, even if I had a celebrity crush that was no actual "threat" to him.
Finally after 20 years together, the poly movement came around and he thought a 3some would be nice, since I was bi.
However, unicorn hunting is stupid and it didnt work out. Finally, he and I split and divorced and now I've been happily poly with a partner I found 3 months after my ex and I separated.
So. tl;dr be true to yourself! My ex was great in many ways, we did share many values, but the pain of having unfulfilled poly feelings for decades (and living under the cloud of his jealousy 24/7) really sucked!
Love withers under constraint; its very essence is liberty. It is compatible neither with envy, jealousy or fear. It is there most pure, perfect and unlimited when its votaries live in confidence, equality and unreserve. -- Shelley
Mags (poly, F, 61) loving miss pixi (poly, F, 39) since January 2009, living together since 2013
"Master," (mono, 36), miss pixi's Dom for 3 years