I'm very glad that you're okay.
I recently witnessed a similar collision. A large crew cab, 1 ton Ford truck hit a small, brand new F150 truck and pushed it into the car in front of it, a small Japanese sedan of some kind. The large truck was probably doing 50MPH at impact. The F150 was stopped, as was the car in front of it.
The impact was so severe that the seat back on the F150 broke, and the lady driving was in extreme pain. She said that she had a severe headache. This is easy to understand, since her brain had just been flattened against the back of her skull. There was considerable damage on the front of her truck indicating hard impact.
The F150 Air Bag did not deploy. She was wearing her seatbelt as well.
After witnessing this accident in progress and hearing your experience, I maintain more distance between myself and the car in front of me. I also glance at my mirror more often.