All seems good then "BOOM" i strike trouble

i am a 15 year old teen and I am a really tiny gymnast. i didnt get my period until the end of last school year which means ive only had 5 menstrual cycles. Im on my 6th right now! i knew right away that pads werent for me so on the first day of my first period, i learned how to use a tampon. tampons worked until about my 3rd cycle when i started getting heavier and heavier bleeding. then i looked into cups and i convinced my mom and BOOM, i got one. i have a diva cup and ive used it for one cycle. inserting goes good and i feel around to make sure it is open and it feels like it but then in about 2 hours, i leak. (i still am using pads because i dont trust myself yet) when i go to remove the cup, i kind of fold it to get it out but then, its no where near full, maybe half way. every time i wipe there is blood too. is it open? am i doing something wrong? when i fold it am i squirting the blood back up lol? Please help. i need this to work!