I didn't have an episiotomy, but I tore pretty badly with Dd. After I was stiched up and 'healed' about 3 months later I started feeling similar. I looked down there with a mirror and I had a small bump. Looked a couple of weeks later and it was bigger. I freaked out and went to the Dr. Apparently the scar tissue can sometimes cause cysts. This one was irritated by sex and underwear.
Anyway, I set up an appointment to have it removed and I haven't had any issues since.