What Causes Pain,bleeding,blackish Color And Swelling In Labia Minora?

Hi. I'm 18. I'm 160 cm tall and 55 kg weight. my left labia minora looks like it's swollen and it's blackish in color. It also bleeds and it's painful when i wear jeans. I'm a virgin and I used to masturbate using water pressure around 7-8 years ago. I no longer do such thing. And I'm not sure when does my labia start to swell because I never actually take a closer look at it. I just did so because it bleeds and I know that it's not my cycle yet. Can you tell me what to do?