Long trans-Atlantic flights are usually at high altitude, and as a result are very stable and turbulence free: additionally, they are usually flown by the larger jets (Jumbos, and the like) which have a very slow take off and landing speed.

However - having said that to try and reassure you - I suffer from exactly the same thing on takeoff and landing, also from very rapid changes in pitch and attitude of the aircraft. The only way I have found to deal with it is fly regularly to get used to the sensation, and I always sit at the back of the aircraft where I find I feel safer and the sensations of movement seem to be less extreme (doesn't match the physics, I know, but hey! it seems to work for me). Also, looking out of the window at takeoff and landing help to orient me with what the aircraft is doing and it makes pitch changes a little more predictable if I can see them.

The other solution is to get blind drunk as soon as you get on board, and pass out!