What about public key? Is it supposed to be shared?
Hey, welcome to the forum.
About your question, that is your Bitcoin address and yes, it supposed to be shared and that is different from a private key, which is means private not to be shared with someone and you should be the one who controls it, exposure may lead to getting scammed.
Note: If you decided to look for the private key, The common format WIF Private key should start with 5, L or K and is 51 or 52 characters long.
But there are other formats that you might need to catch sight of, but those aren't commonly used.
If I'm not mistaken, the private key that starts with the number 5 is 51 characters long and the and capital letters L and K were 52 characters long.
It really sad to the OP and sorry for your loss, because unfortunately, your Bitcoin can't be recovered at all. It's stuck on the address where you stored it on watch-only wallet address.