What have they said has caused this inflammation OP? I have vulvodynia which took years to get diagnosed so understand what a frustration this is. It can be agonising.
I can recommend the vulval dermatology clinic at Guys and St Thomas (london) who diagnosed me.
I'm sure you have gone over all these things but dietary changes, strict regimens of what you use in that are, cotton underwear/nothing tight, no perfumed products, check the washing powder etc. If you use a lubricant be extremely careful what you use. Probiotics.
If it is the pain that is problematic ask to be referred to pain management services, or see to see a specialist womens physio if this is impacting your sex life and this concerns you. Long term use of a prescribed nerve pain medication has been a help to me, and topical use of a lidocaine gel.
Do you keep a diary of when it's flaring up to try and find triggers?
I've been around the houses with my issue for years, it will never be solved and getting help or taken seriously is nigh on impossible half the time. All you can do is trial things for yourself, educate yourself and try to be as assertive as you are able when dealing with the NHS.