Ok looking in to this further and realising I need a LTC wallet, because I've sent this to a BTC wallet key, is there a way of retrieving it?
So you were using Electrum for BTC (downloaded from
electrum.org), right?
And I assume you are using a 2FA wallet and the address you used to receive the coins starts with a 3, right?
If that's the case, just follow this video:
https://www.youtube.com/watch?v=umsIy1ks8vg