Wrong gasket??

[1st_model_a]

I know this will sound pretty basic, but I'm wondering if I bought the wrong rear main bearing cap gasket. I'm trying to figure out how to get the gasket in the groove. It was too long so I cut off the end to make the length fit. The gasket measures about 3-16ths wider than the groove and I'm getting frustrated trying to squeeze 10 lbs of stuff into a 5 lb bag. Doesn't want to compress. Wrong gasket or some trick to getting it to fit? Attached pix of gasket and groove.