Menstrual cup question

So I just started using a Lena cup. I tried to use it last night but my cramps were too bad and it was too painful. So this morning I inserted it, and about 1.5 hrs later I went to the bathroom and noticed it was leaking. I took it out and it was half full. So I emptied it, repositioned it and put it back in. That was at 0730. Then at 0930 I went back to the bathroom and it was leaking again, took it out and it was overflowing full (TMI but it went everywhere!!!). The cup holds 25ml per the packaging. So that means I’ve bled about 40mL in 4 hrs. I’ve always bled heavy but I guess I never knew it was that much. Per what I’ve read 40-80 PER PERIOD is normal. Anyone else have this issue? Can I even use the cup? I can’t change it every 2 hrs...and btw this is only day 1 of my cycle.

Backstory- I was diagnosed with Endo a few weeks ago and using tampons has become impossible, both Bc of pain and heavy bleeding. Pads are just so annoying and they move around too much, causing overflow on my underwear and clothes. Plus using them at night is a nightmare! So I’ve just been looking for an alternative solution.