I can use tampons just fine. I'm going to fiddle with it more tomorrow/the day after to see if I can get the cup in without too much of a struggle, and placing it in the right position.

The problem I was having was that the manufacturers' how to sucked. I tried their way a over a dozen times, and either it would not fit into me at all, or my grip would slip and it would pop open at a really bad place - that's the one where it felt like someone just kicked me.

After that got sorted, I started leaking, and my vulva, vagina, and hand ( from folding, pushing, and pulling in a somewhat awkward position ) were sore. And I had other things to do.