PLEASE HELP!!! Have you been through this before??!

So I started bleeding after sex, at first it starts off brown and then it will mix with bright red then go back to a almost rusty color. This happened earlier this month for this first time and just recently happened again I was just thinking we were being too rough but when I felt my cervix the opening feels a little wider than it should. I frequently “douche” in the shower and warm water and now I’m starting to think I caused myself an infection and I’m getting worried. I don’t have any burning when I pee or itchiness inside my vagina. I don’t notice a “foul” smell, I don’t notice anything but the blood. I have some pelvic pain but not a lot to have me complaining. I know it’s not a STD/I because I have a long term partner and I haven’t had sex with anyone else and I know he hasn’t either... I just don’t know what to do and I can feel myself panicking