Mo2vation,
There are days/dives the Sea Gods have predetermined will turn brown on you. When you hit one of those the ONLY things you can do are either to deal with it or drown. Panic and drowning is usually more work though.
You made a few small mistakes that when added to the mistakes the captain made came up to a brown day, then you dealt with it in a straight forward manner. Good job!
A few suggestions from points in your post.
Mouthpieces:
I've bit through both sides of mine once due to a submerged back injury. Lips alone will retain the reg once the pucker factor gets high enough. Don't worry too much about loosing it unless the tie-wrap fails, then it's time to suck on the regulator stub.
Current: DO NOT depend on bottom critters or plants for a current tell tale. Water right at the bottom can easily be going a different direction from that 3' above it. Check plankton movement for a reliable check, and verify it at several depths on the way down if diving with an anchor line. Direction and drift on sand bottoms can often be checked by using the ripples in the sand from the last storm.
Bow damage and entries:
Try to be aware of where the water and the ship are moving. Time entrances so the water is as high is possible and the ship is as low as possible without having a downward velocity component to add to your fall speed. Generally the "correct" time to step off is is at the point of time when the ship stops going down and just before starts going up. In VERY rough seas hit the water negative, after a complete buddy check and proof that all hardware is working on deck. Level out about 10' down and sort thing out there. Remember that the the main body of the ship's hull will push you out of the way if you are neutral and submerged, along with the water, as the ship settles into the water due to seas. Be very aware that the prop, prop shaft, rudder and bow shearwater won't. These are the "sharp" ends of the ship that can and will hurt you if you get in their way.
Once again, you did NOT freak. You remained in control and handled what need to handled as it came up. I've seen several folks freak, and you weren't close to there yet. Panic at your elbow is bad but manageable and can be a good source of instruction. Panic inside the suit with you is usually fatal.
FT