Would getting a legal divorce mean we're divorced according to Shariah automatically?

My husband and I have been married for 35 years. For years now things haven't been good between us. He had several extramarital affairs and treats me disrepectfully. We kept on trying but it's not working. I keep worrying what will happen if I pass away. I have 4 adult children, 2 of whom live at home and are financially dependant on us.

Previously when I made enquiries I was told that in the case of divorce, my husband would get half of my pension. I worked for 27 years and put all my money in helping him provide for our family. Alhamdulillah, we're married in CoP. For me the worry is what would happen to my children as my son is 32 and has a mental health diagnosis and my daughter is unmarried, pregnant & still studying. Giving away half of my pension would be a knock financially.

I would like to have our civil marriage dissolved but remain married Islamically, at least until I feel I can manage that as well. I know I should have divorced him years ago but I kept hoping he would mend his ways but unfortunately things have become worse over time. I would want him to get some money from my pension so he can at least set himself up with a place to stay but definitely not 50%. He's previously said we should keep the house. He doesn't have a pension benefit. Would getting a legal divorce mean we're divorced according to Shariah automatically? We are South African and follow the Hanafi madhab.