What is the best way to stop everything from piling up inside your mind?

You know what is best for yourself, if that be writing down your thoughts, talking to someone, etc..

Write down what your thinking and if you have a lot of plans get a calendar so you know things that you are doing that day

Journaling can help with that! Also mindfulness exercises. Journaling can help get all the thoughts out from inside, and you can even crumble up the paper + throw it out if they're negative feelings!

Simply trying to collect your thoughts (journalling, using art as creative expression, blogging, etc) can help clear up thoughts a lot. Tackle things one by one, and take the days as they come.

take some times to yourself. take a break from whatever your doing during your day to calm yourself. try meditaion its a good way to clear your mind and let somethings go. letting things pile up in yout mind can harm your mental state and make things worse. theres so many different types of meditaion but if your new to it look up some controlled meditation so you can kinda get the hand of it and learn how to do it. this a personal trick i use when i need to clear my mind. sometimes meditation doesnt work for some people maybe try to find some ways to cope with your feelings like writing,reading,and drawing can help.

You can either write how you feel on a paper, that actually can help us. Writing it down can make us see it from another perspective or talking with someone about how we feel, preferably someone who has more experience on that domain. We tend to keep things to ourselves, either to protect us or those around us but in reality it is not very helpful. We just add more and more and more feelings and emotions till it is too much and then we might act very badly towards others. So writing it down or talking with someone is actually a good thing for us even if we it might seem not so helpful.