In order to be stress free, you have to take things slow and also be organize if its possible. Take breaks once in awhile thru out the school time. There is nothing wrong on taking things slow, or have a few minutes of your own. Its just tells others that you are working hard.
Dont read alot all at the same time. In order to know what you are doing do it one by one. Read one page then stop. Once you stop write down on a journal about what you learn or know about that page. Once you got everything you need in the journal, continue on to the next page and repeat the previous steps. Do this for about an hour and you will be done for todays study session. If you want to study more, study as much as you want. Keep doing the study sessions everyday to get use to the new habit of studing.
Hope this works,