Hard, Grape sized lump near rectum, had GP appointment and urgent two week referral but don't feel reassured

I discovered, when wiping, a grape sized lump inside the flesh near my rectum. It's not on the inside of the anal passage, but can be felt from the outside. It's hard and doesn't move or hurt and almost seems attached to the outside of my rectum but on the inside of my body if they makes sense 

I had a GP appointment today where the GP struggled to find it initially but eventually managed to feel it. They seemed quite dismissive and said they don't know what it is, they can't see any signs of an infection, and referred me to gynaecology on the two week pathway "as a safety net". 

I asked why gynaecology when the lump is near my rectum and they said because "its in the private area". I also asked if I wouldn't be referred for a scan to see what it is and they said I need to see a specialist first otherwise they would just reject it. 

I'm going out of my mind with worry and the appointment did nothing to alleviate those concerns. She didn't ask anything about any additional symptoms or history.

Not sure why I'm posting this, I guess I just needed to get it off my chest but also perhaps seek some reassurance. 

I'm F, 36.