I've never used Lattices before, until I came across it in this cushion modeling tutorial. For some reason, when I use the lattice, it completely deforms my entire mesh, and I cannot get it to behave normally. Here is a link to the zipped up version of my blender file in case it may be helpful. Thanks
You must not scale your Lattice in Edit mode or it will completely screw the object it is linked to, as it's happening right now, because it takes all these scale deformations into account when you link your object to it. Make all the scales you need in Object mode. Then you can enter in Edit mode and move the vertices or scale to deform the object, but before that, keep the initial shape as a Shapekey so you can come back to it whenever you want. So I guess you have to delete and redo your Lattice.