Irritation in vagina?

So a oct 2 I ended my period and I use tampons then the next day I had sex. Well since Friday night/Saturday I’ve begin noticing that the inner part of my vagina is been irritated. I was wondering if I could’ve possibly just made it super irritated from the tampon string (I know sometimes it irritates me a little but nothing like I feel right now) and having sex didn’t help the irritation. Its only itchy/burns if I touch it. No abnormal discharge or smells. Just super red. I want to avoid going to the doctors because I don’t want my mom to question me. Has anyone had something like this? If so when did it get better?