Good to hear you're okay. That must've been horrifying. Thankfully you didn't get injured and didn't hit anyone else.
I've hydroplaned before, but thankfully got out of it. I have had a similar accident, though, and it's my only one:
I was DDing for friends who wanted to go to the bar as a group. One lived near me in the country, so I took a back road to her house. Well, just after I left it started to sleet. I took it slowly, and even stopped behind someone else who was stopped ahead of this really steep corner with a guardrail on one side. He took it slowly, and I did too -- less than the speed limit and I don't think I was going too fast. Well, I hit black ice and the van started to carry towards the guardrail. Thankfully nobody was coming. I pumped the breaks and got the vehicle to a crawl, and angled it so that the bumper would just tap the guardrail on the side.
Well, I don't know anything about cars. While the bumper didn't show any damage, the limited impact and the area at which it occurred snapped the control arm for the front left wheel, causing it to move erratically while driving. I got it home, and my Mom quietly took it in to get fixed so that I wouldn't get in trouble from my Dad, who found out later anyways. She paid for a realignment, the control arm and an oil change.