Mega Menu to Mobile dramas

Hi gang, so I just used the Mega-Menu feature, seemed a bit clunky, but I finally got it to where I wanted it. Then noticed the mobile version was all over the place. The dropdown would disappear off the screen, I couldn’t get to the top menu items once I had clicked a lower one.

Does anyone know of a best practice video I can watch? Im sure it’s just me not being comfortable with it yet.

Thanks in advance