my apple watch disconnected from my phone so know i’m trying to connect it back and it’s asking me for my icloud i used to set it up but i’m not sure what icloud i used

Try using all the apple id's that you remember then;

You can ask apple to remove the activation lock online on this page;

Remove the Activation Lock Here.

Or this;

If you can't remember/gain access to the apple id that paired the watch to the phone.Take the watch and it's receipt with the serial number along with some photo id and any other proof of ownership to an Apple Store and request that they remove the Activation Lock for you.