Technical difficulties?

So I am an 18 year old virgin. I am very comfortable with my vagina, and I decided to switch from tampons to cups! I bought a divacup size 1. I was and still am super excited to use them. I started using them this first cycle and the first day was great! Not much difficulty putting in the cup and not bad to take out. I only changed it in the morning and at night, no leaks, no nothing! Was comfortable (except the stem that I cut off the second time inserting)

Day two was not so rosy... I stupidly decided to go out with the cup in and not prepared for leaks. Sure enough I leaked after four hours? So that was a catastrophe in the public restroom. Needless to say I went home freaked out and put in a tampon for day two. I used tampons for the rest of the night because my vagina was very irritated (I don't know why the cup would cause this?)

Day three I put in the cup, no issues inserting. And I leaked after like 2 hours?! It wasn't even full?! It was like not even a quarter full. I am very distraught, since I seem to be doing every thing right! I put it in with no issues, I try to turn it as much as I can. If I can't turn it 360 then I reach in with one finger to basically circle around the whole cup to make sure that it's fully open. Which it was. The leakage was not leftover blood in the vagina from before. And when I took it out I even heard the seal break?!

I want to know what I am doing wrong? I'm very in tune with my vaginal health and I really do not want to switch back to tampons as they gave me infections. Pads are not even remotely an option for me lol. And I really do not want to pay another $40 for a different cup!!!

HELPPPPP! Haha