You describe your experience as “incredible pressure and pain,” and “deep aching pain.” You also said that you’ve had some varicose veins in your legs and have had some removed. Your research led you to vulvar varicosities, which does sound like a possible answer. These are varicose veins in the vulva, which are not all that common but do occur (often during pregnancy).
There are two options I’d like you to consider: The first is a good pelvic floor physical therapist. She or he can assess structurally whether there is evidence of a source for your pain. A great therapist can work magic! Really, they can.
The second option is a vein specialist. They can do an ultrasound assessment of vein function, even in the vulva, and try to help understand if that is what might be causing your discomfort.
Good luck on your journey!