Feeling puzzled!?!

This puzzle doesn't look that difficult, but I'm almost to the point of calling it quits.  Today I thought I had a good day, maybe 15 pieces put in, but then when I went back to it I realized that some of the pieces just didn't fit where I thought they did.  I have had to rework so much of it, even the edge pieces were difficult.  At this rate I'll still be working on it next winter!