Swelling Near Vagina, Hurts During Intercourse. Is It Yeast Infection ?

Hello, well this is embarrassing. I've been in a relationship for 2 years and recently started having sex. First time sexually active. I'm 19 and we were both tested for all stds and STI's when we first met before we ever had sex. Now the question. I have swelling in my vagina near what I think is the g spot. It hurts during intercourse and can only have sex in the misonary position, but it still hurts. When I'm in what's called the doggie position I want to cry it hurts so bad. You can even feel the swelling with fingers. I've went to a gyn and had a papsmere and was told I'm just sensitive. But sex is just so painful, it can't be that. He gave me medicine for a UTI and it only helped a little. Could it be a yeast infection or even be allergic to my Nuva ring? Please help. Recently I have no insurance and can't afford a ultra sound and just want a healthy sex life.