Dorrie, first, remember your success. You have done a quilt with no instruction!!. Second, what style quilt did you make then? Can you still do something similar now?
I'm not sure that everyone is cut out for precision piecing, and (thank goodness for me), not all quilt designs require it. Those block classes often focus on blocks that do require precision piecing. And they're just not for (me) everyone.
Build on your success by working on a pattern that requires less precision at first. ('Sweet sixteen' comes to mind.) If you have trouble with a 1/4" seam, try a 1/2" seam. Choose block patterns that will allow for squaring up afterward without losing the pattern. I'm a great fan of knowing my limitations and working within that framework. If you work well with pre-cuts, use them!
Today I ripped apart three blocks and re-did them. But that's ok. I won't focus on that. I will remember the six that came out fine. There aren't magic tricks, but you must try to keep it fun.