By “turning out horribly” do you mean that it doesn’t look the way you expected? Is this an art question as opposed to a question about how to import it properly to Unity?
An easy way to see how a frame animation would look, is to open it in an image editor, and put each frame in a different layer. Then you can make different layers visible/invisible to see how it animates. Some image editors like GIMP also has support to animate the whole thing based on the layers.
This way you can move each layer, to make sure the pivot looks correct, also make sure each layer is the same size. Once you are done, you can put each layer next to each other manually, making sure they are all the exact same width/height. I’m not sure if there’s an automated way to do that, but for a 5-6 frame animations it’s not a big deal.