I know your post was made a while ago but I want to check up on how you're doing? Did the counsellor get back to you? Have you since managed to convince your parents to allow at least one tutor to be dropped?
Also based on your original post, I'm assuming you are in year 9 and have 4 tutors at that time correct? If so, that sounds like a really hectic schedule given that this is all on top of rehearsals.
From my own personal experience, I also did tutoring during year 8 and 9, and some earlier years in primary school but what I found was that my marks got better after I quit tutoring and learned to study by myself. Perhaps getting Cs in your report is reflecting the fact that you are overwhelmed from the number of commitments you have right now?
I've also gotten compared to family friends in the past by one of my parents but I've made it clear how I felt about that and how I feel underappreciated, and this, I found, has helped to reduce some of the comparison.
Please know that you're not alone and as @TOM-RO mentioned take it one day at a time and work through it bit by bit. You're a really hard worker and you should be proud of yourself!! 💪
We're all with you in our thoughts!!! 😊💕