how to do well in graduate school?

I am halfway through a graduate program for education. I did great with 30 credits of online classes. Now I have to observe a bunch of classrooms and student teach. I am doing my best to book lots of these "intern" like hours. I have to substitute teach to pay the bills. I feel a bit stupid for getting one small loan after finishing 28 credits. I was so exhausted from all the work that I let my guard down and got this tiny loan with a gigantic interest rate. I think if this tiny loan is the only big oops Ive done in the program, I'll probably be OK. Has anyone out there had extreme fatigue from internet work? I think if I pace myself online work does not have to cause any fatigue. I think "detoxing" from the internet helps, ie, surfing, golfing, hiking, etc. Thoughts? I think the internet is addictive. One addiction can lead to others. In my case I did fall victim to the temptation to get an easy loan when I was not on top of my game. I know some folks do get "addicted" to credit cards and such. Luckily I only "binged" once by taking a loan offer. Anyone out there have similar slip ups when the internet becomes a borderline unhealthy habit, like drinking, drugs, porn or other addictions? Thanks.