Seriously worried!!

Please someone help me.. I know I need to book a doctors appointment, but ive had this big lump on the inside of my vagina for years, in the past ive thought it was my g-spot or something else harmless.. However, recently it's gone really big! And it hurts when I have intercourse to the point where it makes me gasp.. Does anyone have any ideas? In my head im just thinking of the worst 😥