Since your child was born you had to take carer of everything. You controlled everything and had to do so for his or her survival. As they get older your role changes, but there is not clear line or set of rules for how or when your role should change. By the time they are teenagers you are used to putting everything regarding your child before your own happiness. After all that was what was required at one point.
The problem is you cannot continue to live that way and no matter what your child is doing or experiencing, your happiness has to come first. If you are broken and exhausted your child does not have an anchor to come back to when they stray. It is hard to make decisions to practice care for your own social life, marriage, exercise, career, and hobbies while there is crisis with your child. Sometimes being a great parent means putting a hold on parenting for a bit. You only have so much time, effort and energy to put into parenting. Time, effort, and energy has to be put in all areas of your life. The excuses for not doing so are vast but I guarantee that if you bring balance back to caring for yourself your parenting influence will grow.