i’m confused, please help!

so i started bleeding around monday. it wasn’t very much, and a dark brown color, but i didn’t think anything about it because i’m on the depo shot and it’s made my periods irregular. tuesday i was still bleeding and it was a little more heavy so i sent to get some tampons. wednesday it was lighter then the day before. didn’t think much about it because my depo though. then around 11:30 i was walking to class and it felt like my vagina was clenching around my tampon. it was awful and very painful. i hated it. wednesday night i went to my boyfriends house and we was going to have sex but he put it in and it was sore because it’s been awhile, then when he thrusted it hurt really bad and i jumped and he asked if i was okay. i said yes and told him to keep going because i thought it was because it’d been awhile. after like three thrusts i couldn’t take it and he stopped. well, yesterday, my vagina hurt some and was still sore. normally i am the next day after sex so i didn’t think anything about it. but then, today it’s been terrible. this morning i went to the bathroom once i got up and went back to my room to get dressed and was in a lot of pain to the point i felt like i was gonna get sick. i went back to the bathroom and pulled out my tampon and it stopped so i just figured it was in wrong. no biggie. the tampon was basically clean so i didn’t put one back in. today at school i’ve been having pain that felt like something was being stabbed into my vagina. it hurts so bad when it happens that i just have to stop walking. it doesn’t do it sitting down. and then tonight when i got home i noticed i’d started bleeding some more. any idea why this is, or could it just be because my period? i’m not sure, someone please help! here’s the picture of my bleeding just from today.// someone said to go to the doctor and i hate to say it but i can’t. so, please give me other advice. thanks!