A large inky black shape hovering directly about 100 feet off the ground in front of me.

I just got off work and was driving northbound on I-205 going to Vancouver, WA to visit my girlfriend. I was driving a white Cadillac going 65 mph in the middle lane when I looked up noticing a large dark black shape hovering in the sky right in front of me. It was dusk to but this object stood out as blacker than black so I could see it perfectly. As I stared at it I began to analyze it. This is exactly what I thought. I thought of a black plastic garbage bag that that if it got caught on a screw on the sign of an overpass and was kinda being sucked under it. Yet I knew what I was seeing was way bigger than a bag. But I didn't see an overpass or light pole or any wires. So I knew not only was it way bigger than a garbage bag but there was nothing this black object could be hanging off. This black object at my best guess was hovering in midstop about 100 feet from the road directly in front of me. It was maybe sixty feet wide and eighty feet tall and an inky blackness. And I soon realized I'd be driving under this thing. I didn't take my eyes off it and all this happened over maybe 10 seconds at most because as I was about to drive underneath it something like a thin banner or sheet of the same blackness unraveled down from the bottom center of this thing dropping down from it. I watched just stunned as it came lower and I'm almost speeding right beneath this banner like thing coming down from it. It kept dropping lower in a word way almost timing me. It hit the ground in front of me blocking my center lane. It was as wide as my vehicle and the width of my lane a like a thin sheet of blackness. I quickly swerved wildly and in absolute panic barely making it around this thing that fell. As I righted my car I looked in my rearview just tripping on what happened. I saw three other sets of headlights behind me all swerve wildly like I did. I even counted. One. Two. Three. And knew I wasn't the only one who saw this. I started to slow down to wave these cars over but realization came over me of what happened. I got scared and took off speeding as fast as I could out of there.
Now it's been a year but I can't stop thinking about what happened. Things are different. I can't stop thinking about what would of happened if I ran into that black banner like thing that dropped down from this object. And now I'm trying to find those other three drivers and want to see if there were any cameras anywhere near that stretch of highway.
I've looked all over the internet and never seen any encounters of anything like what I experienced. So I'm just idk wanting to tell my story. This has changed my life and I can't stop looking at the night sky wondering if I'll see it again. But the blackness of this object was what was spooky. And shape. There was no lights anywhere. Just dark blackness and that's scary. So yeah that's what I saw and I have become obsessed with finding out what that was.