I don't think you can describe what has happened as "backfiring." That word suggests that it made things worse instead of better. It may not have "worked" in the sense that he is now more interested in reconciliation (yet), but I do think that it has helped your situation, in that you are less stressed and can enjoy your days.
The year I was separated, I was not "dark" but we were not talking R at the time of our anniv. I picked out a blank card and wrote some "glad you were in my life" type of sentiments, very much in the past tense, and I sent it several days before the anniv.
For Lissie: It doesn't matter if you are raising kids together. In that case, "going dark" means not talking about the relationship, and not using the kids as an excuse to call. As in, "Junior just did the cutest thing, and I thought you'd like to know." Contact is just, "when are picking them up, when are you dropping them off, do I need to send swimwear, just do what it says on the prescription bottle," etc. Going to email only or texting works well for some.
just caught up-- I'm not suggesting Lissie should go dark. But don't pursue at this point. This Sunday I wouldn't push to talk, just follow his lead.
