Summarize this article in one sentence.
It’s okay to be sad. While we tend to give a lot of sympathy and understanding for people ending romantic relationships, we don’t generally extend that same courtesy to those who endure a friendship breakup. Yet these are often just as painful.  Understand that you are grieving a loss, and the best way to manage grief is to allow your feelings to flow. It is painful to experience the feelings, but letting them out will help you feel better and move past the sadness. Letting yourself cry if you need to is a good way to express your grief.  Grief ebbs and flows. For example, you may be feeling fine and then you are reminded of a memory of your friend, and all of the sudden you feel horrible again. This is normal, and as time goes on, will happen less frequently. Keep in mind that grief is different for everyone. Allow yourself the time and freedom to grieve the loss of the friendship in ways that feel natural to you. As you grieve, try to maintain your normal routine. Exercise daily and spend time talking with friends and family to help yourself feel better. Talking with a counselor can also be helpful. If you are struggling with your grief and do not feel like it is getting any better, consider talking to a counselor, whether it is through your school or a counseling center. The loss of a friendship can be a significant life event for a person, but sometimes, people can say rather heartless things as they encourage you to feel better. Don’t allow your feelings to be diminished by someone else. If they say, “Stop being so sad, it’s not like someone died!” you could say, “I know you’re trying to help me get some perspective, but I just lost my best friend, and it is hard. It’s okay for me to be sad for a while.” Or, you can say, "What you said seems very invalidating to my feelings. I lost a long time friend, and this is a difficult time for me. I am asking you to respect that, and allow me go through this emotional process right now." Give yourself plenty of time and space to deal with your feelings. Life might feel harder for a while, and you may feel more easily depressed or frustrated. This is also normal as you grieve.  Do things you enjoy that help you feel better. Go for a bike ride, watch a movie with your cousin, hang out with the youth group at your religious institution, or take a bath. Things that you do for your physical, mental, social, or spiritual health that you know help you feel better are actions of self-care. Self-care looks different for everybody. Think of some ways you can practice self-care--maybe you enjoy hiking, reading, or going out dancing with your friends. It could be another friend, a parent, a school counselor, or another trusted adult. Rejection is tough to deal with and having someone there to validate your feelings can often help you through the process.  Find someone you trust who is a good listener. You could say, “Would you mind if I vent? I’ve been so upset about my fight with Kaylee. She doesn’t want to be friends anymore.” If you are concerned about what you tell someone getting back to your ex-friend, consider talking to someone who is not in your social circle, or someone who goes to a different school. You may not be ready right away to think objectively about your friendship, but it will come in time. When you are ready, spend some time thinking about your friendship. Everything can be a learning experience, so ask yourself, “What did I learn or take away from my experiences?” and “Why did this friendship end?”  Look for lessons in the friendship. What did your friend teach you? It might be good stuff, like how to throw a curveball or how to be generous, but you might also have learned some hard lessons. Perhaps you did something to cause your friendship to end, or maybe you learned how not to break up with a friend.  Sometimes friends grow apart as life changes. You and your best friend may have been best friends in childhood, but now that you are in high school, you may find yourselves being pulled in different directions. This is a common experience for many people, though it can still be painful. Consider writing a letter to your friend explaining how you feel. It won’t be a letter they ever see, but it will help you process your feelings nevertheless. After you write the letter, you can read it aloud to yourself and then bury or burn it to help you release the feelings you have expressed in the letter.   Writing a letter to someone without sending it has similar psychological benefits to having a conversation with the person. Trying this technique could be especially valuable if your friend will no longer talk to you at all. It may help you get some closure.  You could write a letter to your friend in a journal or other private place where you feel comfortable letting out all of your feelings. Losing a friend is difficult and sad, but think of the other things in your life that can keep you going. These may be family, friends, hobbies you love, nature, or faith.  Cultivate gratitude and a positive outlook by keeping a gratitude journal.  Practice prayer or meditation to help you stay centered, peaceful, and hopeful.  Try watching inspirational TED Talks online to get some daily motivation. Join a group where you can surround yourself with positive-minded individuals and make some new friends. For example, if you like to read, then you could join a book club.

Summary:
Allow yourself to grieve. Stand up for yourself. Be gentle with yourself. Talk to someone about how you are feeling. Get some perspective. Write a letter you don’t send. Focus on the positive in your life.