The inside of my vagina cavity is swollen, i haven't had sex so therefore i can't have any sexually transmitted diseases or be pregnant.

Vaginitis: You can still get non sexually transmitted vaginal infections like yeast infections and bacterial. In addition you can have some swelling associated with vigorous masturbation. Prolonged use of a tampon may also cause infection symptoms. In addition you can have allergic reactions from certain soaps and washes. It may be time to see a gynecologist for an evaluation.