Hi,
I am a different stage to you (my husband is still fighting his cancer, but has a terminal diagnosis) but I have asked the palliative care counsellor the same question about support groups for people in my situation & widows with young kids. I am 41 and have a 9 and a 7 year old. In my area there is nothing around. The counsellor said they've tried to set up a number of groups, but they just keep petering out after a year or so. I am in a 'regional city' and it is put down to the size of the population of widows with kids.
There are other organisations around like "Parents without Partners" - it isn't quite what you are looking for, but it might help you get out of the house a bit more?
I have a few friends who are single mothers and they have been good. One had cancer herself, so she 'gets it'. My divorced friends try to understand & be supportive of what I am going through, but in all honesty I don't expect anyone to 'get' this journey unless they've been down this road. I know I tried to support friends going through this before my husband's diagnosis - but, once you experience it personally you know that you really didn't fully understand.
Even though my husband is still around I already feel the separation beginning - many more lonely nights while he is fatigued & sleeps early. Many more weekend outings on my own with the kids to let him rest. I know it is only a taste of things to come - but, it is a distressing window into my future. I am sure you understand where I am at.
Hope you find what you are looking for,
Von