Kitchen Large Electric Appliances - Kenmore Refrigerator freezing up

I have a 2001 Kenmore Refrigerator with the top freezer compartment. I had to do some work on the icemaker about two weeks because the water inlet tube was not correctly positioned and water was spilling out and freezing on the floor of the freezer section. That is now corrected. Next we began to notice that water was accumulating in the floor of the refrigerator compartment below the fresh produce drawers. At the same time the freezer section began to frost really heavily like it has never done before. This has not happened before and after a couple of weeks of this the cooling has stopped with a rise in temp. in the frigerator section. The air flow is now restricted because of ice build-up in the freezer section. Ice has formed in the top vents of the refrig. section and condensation is all over the ceiling in the box. I cleaned all of this out a month ago and thought it might be fixed but it has developed again. What have I missed? The model # is 71284100. Thanks for any help.