Menstrual Cups

So, I’ve been trying to use a diva cup for the past few periods and I just can’t seem to get the hang of it. I can get it in comfortably (sometimes for a minute, sometimes for a couple hours) but it always ends up feeling like the little tail bit is jabbing me. Has anyone had trouble like this before? I have the little tail trimmed down to two notches and I rounded the edges where I cut with a nail file. Did I cut it too short? Should it be shorter? Or should I look for a different brand that is smaller or less stiff? Since I got the nexplanon implant my periods tend to drag on and it would save me a ton of money on light tampons and liners if I could get the cup to work.