Uterus hurts (?)

Have any of you ever gotten a strong ache in the uterus area after trying to masturbate? And I say “trying” because I was literally 15 seconds in, hands on the outside, pretty simple stuff, made a little effort with my abdomen I guess? And then I got this sharp pain in my stomach (I thiiiiink it’s the uterus not sure haha I’m not used to having cramps) the pain got so bad I puked. This has happened twice now and I can’t even try any longer, pain also lasts around 10-15 minutes even.

First time I thought maybe I was sick but today I confirmed it only happens with the stimulating effort, this has NEVER happened during sex. I don’t understand what the difference is 😔 or if I should be worried

Additional info: 26yo, healthy, active sex life with only one partner, no history of any STIs or any other disease really, no other symptoms either.