Who Keeps the In-Laws?

Today's kind of a hard day for me. 
No, not because I spent another Hallmark Holiday alone.  I never really spent that much attention to it in the first place, and besides I got to have supper with my daughter whom I don't get to spend enough time with these days. 
Today would have been my 26th wedding anniversary.  I say "Would have been", as four years ago she sat me down and told me that she'd been having a secret affair with a close family friend and did not want to be married to me any longer.  She led a double life for many years and I didn't have a clue.  Oh, there must have been an inkling here and there; a suggestion, or rumbling of something off centre, but really, I had no idea.  I had no reason not to trust her and still firmly believe that if a relationship has no trust, there IS NO relationship.  But I had no idea.  How cliche! 
The person I was, ceased to exist on that day. 
I lost it all.  I lost my spouse, my friend, my family, my future security, my present stability, my retirement savings, and even what little self esteem I had left.  and I had no idea. 
How could I have been so blind?  I felt stupid.  I felt betrayed.  I had the rug pulled out from under me and I felt like I had been shot. 
I don't know to come back from this.  I know others have had messy situations, and moved on.  I know it's something I should do too, but I can't seem to leave it behind.  You've heard the old expression, "fool me once, shame on you... fool me twice, shame on me!" How can you take that blind leap forward knowing there's no safety net waiting to catch you if you fall?  How can you invest yourself to the degree a good relationship requires after all of this.   I don't know how to come back from this. 
I guess, that writing this all down is a small way of coping... a way to put it out there and stop it from rumbling all around my head.   Which leads to today's question:  Who keeps the in-laws?
The ex has numerous brothers and sisters with children of their own, and now, some with Grandchildren of their own.  Some of these nieces and nephews were close and considered by me as family.  Now in those very awkward chance meetings, they don't know what to say to you; you don't know what to say to them and the awkwardness of the whole situation is a palpable pressence that lingers like last night's fish dinner.  They still call me Uncle, but by law, I am their uncle no longer.  I would prefer that they just call me by my name.. but they don't. I still do consider them family, but I know they can't be, because their family is part of the ex's family.
I miss my kids.  I miss my family.  I miss being married.