So I'm a dumbass and have sent BTC to a GEMZ wallet

its confirming on the blockchain and also I can make a watch only address and look at it! Otherwise I can’t see how I can actually get the btc back?

Where’s your GEMZ wallet? Do you mean one on the phone?
Regardless, if you have the private key of the address you sent it to, you can always sweep it from any bitcoin wallet.
Your GEMZ will remain in place.
You can also use Counterwallet for that.