Same for me!! Revision schedules will be different for each person, but maybe look into the Pomorado technique which focuses on short 25 minute study with regukar short breaks! Personally this doesnt work for me I like to work for a few hours at a time but after that I just give up or take a very long break. I usually try to do my homework first and then revise for an hour or two a day taking breaks on one or two weekdays and then working for one day on the weekend.
I think rank your subjects from confident to least confident and focus on the ones you know less. Always make sure you have snacks and water near and maybe listen to some music to help you concentrate!!
Hope this helps x