My condolences to you.
I've never had this happen to me, but I do have a dog that is scared of water (pool, rain, beach).
What we did to get him over this fear is to just introduce him very slowly to it. Like, first, we would go to the beach and he would just sit in the beach tent the entire time. We did this for a few weeks. Then he started to walk with us up and down the beach. After a few months, he would step on the wet sand. He still won't go into the water, but at least he doesn't go psychotic when we go to the beach anymore. He is now comfortable just walking up to the surf which is just fine with us.
Maybe you can do something like that? Like, maybe just let him sit with you in the car without it moving and with all the doors open (hopefully it's not hot where you live). Give lots of praise. Then after a few days of that, turn on the engine still with the doors open. Then after a few days, close the doors and go down the driveway. Then after a few days maybe a spin around the block. That kind of thing.
Hope you all feel better soon.