Hi, amazinglove,
A counselor suggested the following when I was where you are (10 year olds in my case):
Something along the lines of: when people are unhappy they can choose either to work out how to be happy where they are, or they can choose to leave. Daddy chose to leave.
I constantly emphasised that it wasn't to do with them, and also did say that while I wasn't perfect that it wasn't even so much to do with me (near the beginning I had one child cry that I needed to "apologise and get Dad back"). They did feel for a long time, however, that it was because they were naughty, or that they had done something wrong. That has taken its toll, I'm afraid.
My constant saying was "I wish I could wave my magic wand and make this all better, but I can't" so we have to deal with this. (they now laugh when I say that about anything crappy)
As they grew I adjusted what I said to be age-appropriate; there did come a point where I had to say that no, it wasn't right to have a girlfriend while married to someone else.
At the beginning I also said that I didn't really understand what was happening, but that we had to deal with things as best we could. That was true -- I didn't understand. At the beginning I did say that I was sure that he loved them, but that he wasn't happy right now and was working on it. (That is what he had said to them once). I think I stopped saying "I'm sure he loves you" after 3 or 4 years, though.
But it didn't help that when my daughter, when visiting him, asked him why he wasn't at home he replied that he had a new life now. That hurt her a lot, not to mention hurt me.
As they grew I did tell them that they could tell him how they felt the same way that they told me if they liked or didn't like something. I think you're telling them that they don't have to reply, but of course can contact him whenever they like is good. It's so hard for them to navigate this.
My children were afraid to say how they felt; they were scared that he would distance himself further. They felt punished.
There were definitely times when I told him exactly how hard this was for them, that may not have been a good idea, but it certainly happened. I definitely didn't handle everything perfectly, but I handled it the best I could at any one time.
What I don't necessarily agree with is that very young children are suddenly expected to navigate horrible situations by themselves -- so the first years I did speak to my then H to say what the children did and didn't want to do. I didn't call him to say things necessarily, but I did, for example, relay the message that they wanted to see him on his own, rather than with an OW (he went through many). As they grew they then did this for themselves.
My approach may or may not have been right, but I could only do the best I could do, as is true for us all.
What I didn't do was text him to ask him to contact them, though. Not that I didn't contact him, I did (probably far too much in the early years), but if I had something to say I would wait until he came to pick them up or something.
amazinglove, this really sucks, and however hurt we ourselves are seeing what it does to our kids is a million times worse. I think it is OK for you to say that you are hurt and confused as well, but that no matter what, you will be there. That I found was most important for them -- for quite a number of years after he left they wouldn't let me out of their sight, they absolutely needed to know where I was every single moment, if I was seeing a friend they needed to know who and where. I don't think you can reassure them too much about that. And of course always be there when you say you will be.
My kids caught me crying sometimes (I tried to keep that out of their sight); all I said was that things sometimes got hard for me, but (and this I think is crucial), it wasn't to do with them.
I think you are doing brilliantly; I took years to sort myself out. I'm sure I made many mistakes with my children as well, but what I found always helped was to say so if I did something wrong, and constantly reassure them that I loved them and that I was there.
The one thing I never did was say anything along the lines of this being a joint decision. None of this "mummy and daddy don't want to be together any more", which I understand many divorcing couples say. I tried very hard never to "bash" him, but I didn't say that we had agreed this. I did sometimes have to say that this is what it had to be because he had left, though.
Looking back on what I have written it sounds so glib; I bet if someone dug through my old threads they would find much more of the complete mess that I was.
But what I can say years later is that my relationship with my now adult children is very strong, and my former H doesn't have one with them. My children tell me that they think I handled things well, from what they can remember.
Just keep going -- one foot in front of the other.
xx