I did a similar thing on my first jump. I was concentrating so hard on getting my exit count right and not freaking out that I forgot to arch before the sensory overload hit.
When I realised that all I could see was blue I snapped out of it, arched (JMs re-attached), completed the bits and pieces, got down safely and passed.
Not finding the pilot chute I think is pretty normal for a first practise pull in the air, but you didn't get that far due to being owned - thus you not finding it at pull time.
But hey - sounds like you had a stable freefall and altitude awareness at pull time, so it's not all bad.
I agree with everyone above. Try again!