Hello! I've been reading along and I see a flaw in both your and Tea's arguments. It's always "I've already done that. Tell me something new."
Something new? No, go back and start from the beginning. You are missing a vital part of life. Don't give me all the "if she was sick" balogny. Start a clock. Set a boundary. Start over and do things many times. Ram your head against the wall, breach the gap. Think if this as your "D" day. There is an insurmountable obstacle. Your job is to make it less so.
So you've tried something. So what? Try again. If you want to continue to live in a sexless marriage just continue with what you've done. It's obviously working for you, right? I mean, you think you've done it all, seen it all and you're willing to just sit there and let your life drip away until you're too old and feeble.
Sex is good for you! If you are in an unhealthy relationship and your partner doesn't want want to change make a decision! Would you still be there saying "but I tried to get her not to drink" or "I tried to convince her not to use drugs"?
I wouldn't and I don't think you should either. Now, get to work on it.