How can I stop thinking about him/her? Why my heart hurts so much?

it because you still care about that person. to get over him/her the best thing is to get busy and do things that make you happy, go out with friends and be active, that's the best way to get things off your mind and move on. try and find some positive ways that make you feel better about yourself, get a hair cut, get some new clothes or even go out and do some physical activity also by doing that the person that you are thinking of will find your positive change very attractive.

Distract yourself. Go do something to keep you busy like hanging out with your friends of doing chores. Whatever you want. Just distract yourself the best you can and then they will leave your mind

Focus on other things that make you happy--your family, your friends, your hobbies and other activities. Working out helps, any sort of distraction. Soon enough, you'll find yourself never even thinking about him/her.

Allow yourself to be distracted. Heartbreak can take time to heal, so also give yourself some time. Your heart hurts because you loved that person and you're no longer "with" them, so I suppose a bit of your heart was with them and since they don't exactly return your feelings, it hurts you. Love is a mysterious thing. I hope things turn up for you.

Heartbreak can be emotionally painful and most of the time it feels like you'll never get over them. Time is the best thing to fix a broken heart. In the mean time try distracting yourself with stuff that makes you happy. Reread your favourite book or have a movie marathon. Soon you will forget about them.

Start putting yourself first! keep busy and positive, don't be around negative people, take each day as it comes, don't rush into anything

You can't stop thinking about them because you saw that them are the happy thing which has done in your life and you won't stop thinking .. It's a normal thing .. You will forget by loving a new someone who changed your life to the best and you will forget by the time

Heart ache can last a long time, a really long time. Over time it will go away but all i can say is try move on to someone else if possible

Take up new activity or hobby that would help you get out of this situation dont try to control your emotions let it go .get out with friends and family

first remove his/her number from your phone so that whenever you go through your contacts you don't remember him/her. second distract yourself in activities with your friends third try not to relate everything you do or everywhere you go to this specific person of course you are gonna get hurt because you lost someone you cared about. but you gotta see it in another perspective. see it as if you lost someone to win another person who will be better in every which way.....