I seriously doubt that you require a NO boost because you probably have high levels and certainly above normal which can happen with autoimmune illnesses.
If anything reducing your levels would probably be of benefit. B12 can help with that as it can with increasing T suppressor cell activity if a sufficiently high dose is taken.
NO tends to lower BP by dilating the blood vessels, what is your BP like? It might indicate whether your NO levels are truly high.
I don't think that this is leading you down a route which will benefit you.