Hi Rebecca
I too have lichen sclerosus with VA, and also a prolapse, so I have sympathy for you. I will tell you what has helped me, following seeing a dermatologist and also paying to see a private pelvic floor physio, for the prolapse primarily but she has been very helpful with the lichen sclerosus too.
The vulval dermatologist prescribed a pea sized amount of dermovate ointment to be used every day for two weeks primarily and then every other day for two weeks and then twice a week as a maintenance dose. She also prescribed using a toothbrush head amount of ovestin every day (and to continue to use every day on an ongoing basis) to be rubbed in around the vulval/clitoral area about ten minutes after applying the dermovate. I did this for two weeks and it really helped but when I tried to drop down to every other day the symptoms came back with a vengeance. The physio then suggested that I should split the pea sized amount to half a pea sized amount morning and evening, and then to try dropping it down but to drop it down to half a pea sized amount once a day, which I did and I am now in a place where I use a third of a pea size every day, rather than one pea sized amount twice a week. I continue to use the ovestin, and also use vagifem internally for the VA.
I have also found that castor oil is good to use as a moisturiser externally (this was recommended on a lichen sclerosus website/forum). Also go commando as much as possible. I no longer wear trousers, apart from occasionally some very soft harem trousers, and wear skirts/dresses with crotchless tights in the colder weather.
I wash with hydromol and have showers rather than baths nowadays.
These are all things which have helped me. I still have some times which are itchy/burny/painful, but using the above regime has definitely made it more manageable and the skin definitely looks healthier than it did.
I hope some of this may help you. It is a miserable condition and I hope you can find a regime that works for you. xx