Hi Wench - and welcome !
My first thoughts............
I'd suggest you take yourself - and what feels TRUE to you - very seriously because it will set the path for your life going foward.
The difference between being & living poly is dramatically different that living a monogamous lifestyle. It's more work and potentially more rewards.
But you are already married and you have to assume that if this is "truly" you - and what you want to be happy & fulfilled - it may require a whole different cast of characters going forward. Big decision.
Go slow, learn and have no assumptions or expectations. You'll find it a brave new world !