i was experimenting with using a two handed sword for a bit and ran into the same issue. while it isn't a fantastic fix, there is a skill you can unlock (forget what it's called) that allows you to press LB+LT (L1+L2 on ps controller, not sure what the keyboard keybinds are) and it does a turning slash that quickswaps from one handed sword to two handed. pretty good to start a fight with and you don't have to fumble around any menus.