Take. It. Slow.
Unless you are paid to ride your bike professionally you are riding for the fun of it, whether that’s recreationally or racing. If you don’t enjoy it then don’t feel pressure to do it.
You clearly enjoyed being on the bike in the past and I’m confident you will get back to enjoying riding. The fear of crashing does eventually go away. I got hit by a car almost 18 months ago and I’ve only recently started to ride as confidently as I used to. Don’t worry about trying to re-build confidence or reduce fears because it will happen all on its own.
In the mean time, be prepared to get the fittest you’ve ever been by doing all your riding indoors 