Was driving my car (automatic) up hill yesterday after turning a corner onto the hill I noticed the gears stopped changing the car was revving supper bad but I couldn’t stop on the hill to check what was wrong as there were cars behind me, by the time I was able to pull it it must have been about 3/4 mins of the car struggling and screaming at me coming up hill.

When I stopped and checked for issues I noticed my gear stick had knocked out from D to D+ -

When I shifted it back I took it for a short drive before coming back home where all seemed to me ok, I’m just wondering would I have done major damage to my car with this and why would it have just knocked out of D while driving?

I’m hoping it’s all good I know 0 about cars it’s my first car and I just bought it from a dealership 3 months ago