Please comment with advice!!

Okay so this is really embarrassing and I'm honestly getting worried about my health and I really want to know what I can do to make this better. Okay so here's a little background information on me. I'm 16 and have type one diabetes and am in a relationship that has been going on for 14 months. I'm on birth control (the implant). My boyfriend andI have been having sex for the majority of our relationship and we hardly ever use condoms. Since I got on the implant (in February) I've been letting him finish inside me (yes, I know I shouldn't) but I always douche after and take a bath or a shower when I get home. We only have sex like once or twice a week so it's nothing crazy. But recently I've been having some problems. Like my genitals have been itchy and red and swollen for like a month. I thought it was because one time after leaving his house I went straight to a friends so I didn't get to take a shower and I just thought it was a bacterial infection or something so I googled how to take care of it and tried different home remedies and we stopped having sex for about two weeks and I thought it was getting better, which it did get a little bit better. But we had sex again just a few days ago and it's going back to how it was, just not near as bad. I don't know if it's because we have too rough of sex or if it's because he cums in me or is it because I'm not clean enough? I prefer baths to showers could that be why? I just really want other women's perspective on it before I go to my mom because She doesn't know I've been having sex and she'd kill me if she found out but if it's something serious I might have to tell her. I just wanted so,some elses opinion first. So please if you have any advice please comment I'm getting desperate. Thanks so much