I Have A Bump Just On The Inner Side Of

I have a bump just on the inner side of my labia. Discovered because there was a slight itch. Now is very tender. It's under the skin. I have not been intimate with my husband for 4 yrs and we were intimate 2 weeks ago. He has cheated before and may be now. I've read all I can re herpes, cysts, etc. I'm scared. No health insurance.