You are a strong and brave girl. No one will send you back to the parents if you are afraid.
But you need a lot of patience will be needed time to negotiate with your parents that you are going to travel home to Bangladesh.
Swedish authorities can prevent your parents to see you but they can not decide that you are going back it just the parents.
When you are 18, you are free to decide for himself.
You have to look at your situation that it could take two years, but hopefully it will be faster to come back.