Are there any single mothers of two children who could share stories of how they make things work?

I have a 6 year old and recently found out I am pregnant with my second. Me and the child's father are not getting along and I'm afraid I will have to go this alone. I considered abortion & adoption but couldn't bring myself to do either. I am a graduate student entering my last year of graduate school. If all goes well, my baby will be born 3 months prior to me completing school. I live in California (for resource referral purposes) and I am concerned about being able to devote time, energy & nurturing to both children. Anyone out there with experience in this area? I appreciate all comments...