bolete, Did or does your W have an emotional or sexual relationship with another woman? Difficult to work on the R for 2 people. Even more difficult something if 3 parties do not agree on everything.
You stating you are HD struck me funny when you wrote that no sex for 4-5 years. If that were my case, I would consider myself LD and still sex starved.
Because your case is out of the norm, I really do not have any sexually related advice. Just the 2 or 3 people comment above.