unusual bleeding and a huge clump right after protected sex

I just turned 18 and I have been with my boyfriend for a yr and a half. We have unprotected sex however I do not let him cum inside of me. A few times in the past during and after sex i would start to bleed from my vagina.At the time I thought that maybe he was just to forceful or possibly hurt me.Recently I started birth control patches, I have been on them for 1 week and we had unprotected sex. Afterwards I saw a little blood but I thought it would go away within a few minutes like always, but when I stood up I started gushing out of me and a huge clump about an inch long and half an inch wide that looked like dark colored jelly came out. I have had small clumps like this before while i was on my period but never this big and never in between my period. I have also noticed that my breast are very tender all of a sudden, and my stomach has a sharp cramp every now and then.My boyfried has had sever sexual partners but he said he got tested for STDs before he met me and he is the only partner i have ever had so i don't think it's that. Also for several months now i have noticed i thick white discharge coming out that has a foul-fishy smell and during sex i often smell this. And between my periods before i used the birth control patches i was spotting accompanied be cramps. What could be causing all of this this???? I am really scared and i do not want to go to a doctor. Any advice you could give be would be very VERY appreciated!