New to Towing

Hi, me and my wife recently purchased a used Ace Jubilee Ambassador 2 berth caravan. This is my 1st caravan and also my 1st time towing.

We have just done our first weekend away in it and it was great apart from towing. Over about 45mph there is a lot of feeling from the van pushing and pulling ( it's a bit like turbulence in a plane) and we find it quite uncomfortable for both driver and passenger. Is this normal and if not any ideas as to what is wrong. I am taking it back to the dealers in a few weeks for then to check it over but I'm interested in your opinions.

I think it was loaded right and looked level with my car which is a 2006 Rav4 2.2 diesel.

At slower speeds it was not as noticeable, apart from this we had a fantastic trip and cannot wait to go away again.