I'm terrified of motorways, dual carriageways and slip roads. Yesterday my driving instructor took me on a slip road without warning, and I didn't merge properly, the cars behind me tried to overtake because I didn't know what I was seeing in my mirrors at all. like I could only see behind me because the slip road comes in at an angle you know? My last instructor said "quick glance to your right and you can join if its clear" and I prefer his method because im so nervous I just overthink the mirrors too much. Does anyone have any tips? Is it safe to do what my last instructor says and not check mirrors?