Hi Charliemouse.
No not been on QE2 or QM2, in fact this is my first cruise with Cunard, however there were seasoned Cunarders on board and they were complaining about the movement and stated that the other two did not suffer the same way. QE2 has a 'sharper' bow and cuts through the water. Yes she dug her bows in, but she is sleeker nearly all the way up to the deck. Her action is similar to a chopping action with the side of your hand, but Queen Victoria, if you look at her bows is sleek at the waterline, but further up is shaped like a saucer, consequently where the hull is flat bottomed, she rides up over a wave and then crashes down into the next one and it is the 'saucer' hitting solid water which causes the shudder and the bang.
Yes QE2 had to slow down and it was reported elsewhere that it gave her a rougher ride. The report did say that at night she sped up to give her passengers a better nights sleep then returned for Queen Victoria in the morning. How true I don't know.
Please please please do NOT be put off cruising by your first cruise. You were very very unlucky both to have bad weather and to have a bad ship as well.
My cruising experience has been three cruises into the Med on Thomson ships, a Round the World on P&O's Aurora which took three months, January to March 2006. A cruise, again on Aurora down to the Canaries in November 2006 and this will interest you. When we left Madeira to return to Southampton, we hit bad weather. The waves were 10 - 13 METRES high (Captain Ian Walters estimate) and I have a video of the seas from my cabin balcony. I then pan down to the balcony rail where my mug of coffee is. The coffee is like a mill pond and hardly moving. We got to Southampton and we were continuing on the next cruise so did the Bay again. Aurora is a different shape and the ses roll round her and she cuts through them. Wonderful sea kindly boat.
In March last year I flew out to Barbados to join P&O's Arcadia and brought her back across the Atlantin to Southampton. No problems.
You were very very unlucky. Please do not be put off. I am back on Aurora for Greenland, Iceland and Norway in June and a completly new ship and line, (still Carnival), Diamond Princess cruising New Zealand and Australia next Winter.
If it is of any help and comfort to you and your boyfriend, my first "Cruise" was with the Royal Navy, throught the Bay in 1959 and I spent 3 days on my back

we went to Gibraltar and then were told we were having a 3 week excercise in the Bay of Biscay

Like a Mill Pond
Don't be put off. There are better ships on the water.
Mike