I feel your pain. I went through the same thing. One of the things that worked for me was to make the machine go really fast and my hands went fairly slowly.
I bought some really cheap muslin and made a gazillion pot holders, place mats, etc. to practise.
I also found that the batting made a difference. I find it easier to FMQ with a cotton batting rather than the polyester. The thinner the better.
I also visualize what I want to do before I actually do it.
Don't give up. Just keep practising on something that doesn't matter and you will get better. Don't worry so much about the design, get the feel for moving your fabric and the design quality will come later.