PIB - I congratulate you on your choice to go back to Grad school.
Quote: Afraid that I'll be so busy that I won't get any time with him...and he'll leave.
When I went to law school I had to do it at night and work 40+ hours /wk. Although I was already D from my 1st marriage I felt that to keep my sannity I had to make time for me so I joined a pool league 1 night a week. It did not detract from my classes and gave me a much needed break from work as well as all the studying. And it gave me some social interaction as well which I believe kept me focused.
I would suggest that you set aside some time for your H while going to school. of course take advantage of all the little times together that will pop up, but the planned time will be special.