How important is a 4.0 GPA in high school? Spoiler alert: it's not all it's cracked up to be. I'm not saying that your grades don't matter, but you shouldn't only put all your effort into getting straight A's if it means you have no extracurriculars.
There are a couple of instances where straight A's may not be the end all be all:
You only do school. All your time is devoted to schoolwork which means you have no participation in extracurricular activities like volunteering, part-time work, sports, or arts. There are two reasons that this is hurting you: 1) if you are planning on applying for college, institutions want to see a student who is involved in their communities. They are seeking individuals that are willing to participate in events – they want engaged students ready to get involved and try new things. 2) You are sacrificing your happiness for a 4.0 GPA. I promise you that your mental wellbeing matters more than an A. You should still have time to do things you enjoy, spend time with your family, and get a full nights' sleep. You shouldn't let your grades tank so that you can only enjoy yourself, but getting a B because you found a healthy school and life balance is just fine.
You're taking easy classes so that you can get an A with less effort. If you don't have to put any effort into any of your classes and you are always bored then your classes are probably too easy. If you are planning on going to college know that they do pull the offered courses to see if you only took the easiest classes. Colleges would rather see a B in an AP course instead of an A+ in a regular course. You don't need to overload your schedule with AP classes (take it from the girl who took 5 APs junior year) but consider signing up for one or two to challenge your brain. However, if you struggle with a subject then don't overextend yourself and take the AP or Honors version of that course.
You are not planning on going to college. If you are planning on going to a trade school to learn a hands-on skill, then you should focus on figuring out what trade you will be studying and where. Trade schools may still consider your GPA, however, they realize that your GPA does not always correlate with your ability to do a good job with a hands-on skill. Not everyone is meant to learn in a classroom and that's ok! If you are hands-on learners you may struggle in lecture-style classes, but should always try your best at school. It's ok if you don't have perfect grades due to your learning style.
You or your family is going through something. This circles back to #1 a little bit, you and your family are more important than a 4.0 GPA. If you are going through a tough time then it is important that you take time to take care of yourself. Same with your family. If you are going through something be sure to talk to your teachers and guidance counselor, they may be able to help you navigate what you are going through. Just remember that your and your family's wellbeing comes first.
If any of these situations apply to you I encourage you to be ok with not having the most perfect GPA. Remember that straight A's do not define you, you are so much more than your grades.