Can’t use the cup…can’t use anything else

So I had surgery to remove a tumour and found I couldn’t wear disposable pads. They made my cramps worse and caused a ton of pain. I tried using a cup and it felt way too tightly sealed and unmoving, yet when I went to take it out over a toilet it just fell out and went in the toilet, which self flushed and took $50 literally down the drain. I don’t think I would have washed it and stuck it back in after it went in a public toilet anyway,

Are there any eco friendly solutions for heavy flow that don’t like, fall out? I used to use a pad with a tampon. Tampons don’t fall out so it’s not that I’m just so loose I expelled an entire cup.