I'm wondering exactly what "quilting foot" you have. A lot of feet for quilting are actually meant for piecing. A quilting foot for FMQ needs to be a "hopping" foot such as a darning foot. A hopping foot has a spring in it. If you hold the foot in your hand, you should be able to move the foot up and down on the shank because of the spring. I am wondering if you have the right kind of foot for FMQ.
Some quilters actually find it easier to FMQ with feed dogs up. It depends a lot on the individual quilter and the individual machine. For machines that do not have the option to lower the feed dogs, you can cover the feed dogs. You can just tape an index card over the feed dogs and make a hole for the needle. Alternatively, some people punch a hole in an old credit card or driver's license for the needle and tape the credit card over the feed dogs.