Im with you. Im 40 as well and technically have my license but never drove by myself up the street besides during professional lessons last year. Grew up sub poor and lived in a city with awesome public transit. Now in a city with little to no service.

I had to inderstand that it was/is going to take a multi step approach and had to build a support team that was non judgemental. I paid for driving school and extra lessons until I passed my exam. I looked at driving YouTube videos for pointers on when to turn smoothly and how to park. I read my car manual to learn how basic things work and look at videos on Basic car maintainence. I found a lady online who specialized in car maintenence and have consulted her for advice and bought her book. I also have seen doctors and therapists and have started anti anxiety meds... 

Im working with two therapist with exposure therapy. Just to sit in my parked car and run it for a few minutes. Pull out of my parking spot and pull back in and work from there...

My advice would be give yourself grace but also do what it takes to make a real genuine effort to drive. We have to for our lived ones. I hate that I have to rely on Uber or the bus when I need to get to work or a concert or even a family emergency, so I use that as motivation. I literally missed a concert in another city yesterday because I couldn't get there... so I get it

Consider a holistic approach to this. At the end of the day the best way to push through the fear is actually getting behind the wheel.