I certainly found when I was studying in secondary school (high school), I mapped out the entire syllabus for a particular subject (say Biology) and assigned a week to each topic. I assembled past exam papers as well as any other sorts of practice tests that I could use for revision. I used 2 weeks for this.
I was pretty ruthless about what I allowed to impinge on my time and kept distractions to a complete minimum ( and that included time with my parents although they were very supportive). I passed all of my exams with As.
You have to focus and decide what is important to you. Your parents will always be there and your girlfriend, once you explain things to her, will be supportive as well.