It is insanely hard to study with a baby! I took a 4 week break during the summer and started up again 2 weeks after my son was born, and continued to finish off my education (he was 2 when I finally finished). My best words of wisdom are...see if whoever is watching your son while you are in class can keep him for a little while longer during the day so you can stay on campus and study! I would purposely schedule my classes so my day would look like this:
10 AM (class)
11 AM (class)
11:50-1:50 (break)
2 PM (class)
Something along those lines always worked for me...sometimes it meant that I had to take classes that weren't my top choice, but it also meant that for almost 2 hours 2-3 times a week (depending on if I went MWF or TR), I had time for me to study, get work done, or drink a coffee and read the paper!
If you can't schedule yourself this way, may I suggest hiring a young girl in the neighborhood to come over a day or two a week to be a mother's helper? Around here, you only pay them about $4 an hour (because you are technically at home), but she could take your son off of your hands while you could get some work done.
If none of these options work, then I suggest trying to rest a little during the day so you can stay up later at night. My son also went through a stage where he wasn't consistently napping, and I found that unfortunately, I got quite a bit done at night time when I knew that he would sleep some.
Finally, your son shouldn't need to get up in the middle of the night at his age, so you may need to just give some tough love so you can get some sleep and be a productive mom and student during the day!
Good luck!