Can I claim for maintenance for our 3 children against my husband (still married)

Good morning, I have been married for 5 years now and my husband has been residing in the Northern Cape (650 kilometres) before our marriage. We have 3 children together. He had filed in for a divorce last year in April (2018), in the month our son (last) was born. I had begged him to withdraw the divorce. This was because of being afraid of going through the divorce process of the kids being homeless, new baby was born, and wanted to avoid that traumatic experience for my children. He had agreed to withdraw the divorce. This had made the situation very difficult for me in terms of being married to someone who had no love and affection for me anymore. I kept on holding on for the sake of kids. He has also been pretending but now it has came to a point whereby we both cant anymore. He is leaving his life in NC and I had accepted the situation. He will be filing in for a divorce, this was the last conversation I had with him (this is what he has said) but my issue is that he is no longer supporting the kids as he should. Can I claim for a maintenance whilst we are still married or during the divorce process? If so, where can I get help with this situation...