You're correct, my electrum address does begin with a 3. I was wondering if there is a way to move my coins to a normal BTC address within the Electrum wallet. Otherwise how in the world is there a video outlining how signing is indeed possible in that video?
There was in fact one comment in that video with the exact same problem as myself. The answer was that perhaps he had an old version of Electrum. As far as I can tell I have downloaded the correct version.
I, in fact, moved all my BTC to coinbase only to find out that signing is no longer possible there and paid £20 in BTC for the privilege! Ah well, its the way of it in crypto land.
Ill likely end up using Trezer wallet now. I just wondered whether i was too hasty in giving up on Electrum and that there is in fact a method of doing it there.
Thanks for your responses people. Great and active community on here!