Vaginal problems and pain during sexual

I have had this lump inside my vagina for like a year minimum. It’s about two to three inches in, on the left side and it’s large. It doesn’t always hurt but it’s very painful while having sex. It hurts so much if he touches it. The doctor told me she couldn’t see anything. I don’t believe her. If I can feel it just by putting a single finger in there then how can she not see it. I’m just very concerned and the doc did nothing to help. She said it normal for sexual to be painful sometimes but this is every single time and it’s a very sharp pain. It even hurts after sex is over. If anyone has experienced this or has any professional ideas or anything really, please help me out. The docs don’t seem to do much for me.