I don't know if my sewing machine needs to be replace/fixed or if it is operator error.?

I think most sewing machines are designed for a seam width that is approximately the width of the gripper foot so if you try to do a seam that is less than that things are not likely to turn out well. Why not treat yourself to a sewing cl - I did and I'm much more confident with my machine now and learnt all sorts of hints and tips that the professionals use that I didn't have a clue about before.