I need advice for menstrual periods and soft cups immediately!!

[Wolfprincess1997]

When I was 14 I started using the depo shot. I stopped when I was 19. I didn't have a period the whole 5 years. I got them back about in june. It is now September. I used soft cup July, August, and this month. I started my period yesterday afternoon. I put the cup in at 6pm. I didn't think about changing it before I went to bed because I usually wake up early, but I went to sleep and didn't wake up until 12pm. So I had it in for 18 hours. When I woke up, I immediately felt so sick and dizzy, I could barely walk because my whole pelvis area  felt so swollen. I rushed to the bathroom to get the cup out, and when I pulled it out, blood ran out of me like a water fall. Now I have another cup in, but I still feel extremely dizzy and sick, and my whole pelvis area still feels really swollen and I still can't walk. I just need to know if this is related to the soft cup, or if I should seek medical emergency help!!