I was thinking something more like the following. I have omitted a lot of steps in the mechanism, but here is some of it.
The three membered rings in your mechanism are too unstable to form.
Also, in your second to last step when the oxygen -ve charge electrons fall back in, they will eliminate OEt because it is a very good leaving group so you wouldnt get your product. Think what product will actually form in this instance, if this was the case.
Hope this helps a little.