Your pattern is probably contributing to the problem because it requires you to turn the quilt a lot.
I tried hand quilting without a hoop, but actually found quilting with a hoop to be easier. Also, my stitches (especially on the back) were not nearly as nice without a hoop.
Here is a link to the hoop I really like. It is easy to turn the hoop in any direction and to any angle for a pattern such as yours. If you do use a hoop, just remember that the quilt is not supposed to be drum-tight. Keeping it very loose (I was told a fist-width of "give") makes it much more similar to quilting without a hoop in that you are very free to manipulate the fabric onto the needle.
http://www.keepsakequilting.com/productdetail/9113.htm