reminds me when I picked up the sport as a sport. when I was a kid it was never an issue. but suddenly I had a "road bike" oooh ahhh and now there was traffic and "cagers" ew yuk. oh yeah, now we all had to wear helmets, are you freakin kidding me? anyway it was a real adjustment going from the '70s to the 2000s.
first day I pulled out of the condo complex onto our first big road what struck me was the wind noise, the twitchy response to steering and the close proximity of the cars passing me. there's nothing like the fear of death to keen your senses! courage isn't the lack of fear. it's ability to persevere despite it.
start on quiet roads and sunday mornings. research proper technique. look on you tube too, there are plenty os safe cycling sites that show exactly how to handle road riding with traffic. don't be a ninja or a salmon. stop for lites and stop signs because its amazing how quickly a car can appear out of nowhere.
don't let getting buzzed make you a raging maniac that wants to catch the driver at the next lite so you can punch him in the head. the cagers don't really want to kill you, but you'll meet many an a-hole. just shake it off the best you can. come here and vent if necessary.
education is your best wingman.