How do I deal with my emotions about not seeing my son very often?

About a year ago when my son was 5 months old, his father kicked me out because I had some emotional issues going on. I went on to become homeless due to not having a job and no family to turn to. I have since been to therapy and continue to go and am starting school soon so I can develop a career and stop just having jobs. My son's father is on welfare and has not worked for more than 4 years. The custody is legal and when I was having my problems last year I gave him majority custody. I regret it all the time. I had the chance to have full custody. This is my only child and I am missing out on so much. I sometimes have a very difficult time dealing with the emotions that come with being away from him. What can I do to ease my pain until I can get to court to get more custody of him?