How many successive nights have you "suffered" through in the hammock? It generally takes the third night for my body to adapt to a new sleeping environment, either on the ground or in the air (and that's three nights, every time I switch back and forth).
My first night in a hammock was horrible. It does take a lot of extra work for some of us to get it just right. It sounds to me like your issue is not any particular style of hammock, but rather your body adjusting to the change.
Definitely a good idea to get used to it before heading out, but don't worry too much about getting on the trail - hike yourself tired enough and you'll be able to sleep anywhere.