When you aren't in love with your SO anymore..

I'm so lost. I share 2 children with my SO. I'm also a stay at home mom. I don't work and I'm facing some serious medical issues. I've been unhappy in my relationship for a very long time. We have absolutely nothing in common. We barely have sex (he never wants to) and I don't know how I can be with someone I just don't love. He's not a bad person or a bad father. He's a good provider but our relationship is basically like roommates. I'm staying with him because I feel trapped. I don't think he loves me either. Maybe were both staying because it's just.. convenient. And of course we have children together. I don't know how to deal with these feelings. Any advice?