Unfortunately, it often happens that after a relationship breaks up, one of the parents seems to “drop out” of parenting.
If this happened in your family, try to find support among other adults - this could be your relatives or friends, as well as a psychologist.
But you shouldn’t seek comfort in a child – little children are simply not capable of becoming a support for their parents, because they are not ready for this.
Often mothers (or fathers), left alone, tell the child that the other parent loves him, and does not appear in his life only because he has no time now.
This is also not something you can do - as a result, the child will develop an incorrect idea of love.
This cannot but affect how his relationships will develop in the future.
Don't understand why your partner behaved this way? Don't lie - tell your children so.
There is no need to invent anything about your ex-husband – neither good nor bad. You can only speak for yourself – try to convince the little one (even if you are dealing with a teenager, not a baby) that you will always be there.
For example, you could say, "I really don't know why this happened, but I'm so sorry. I'm here and I'll always be there."
This way the child will understand that he has someone to rely on and that he is not alone.