Although surrounding yourself with friends is definitely helpful and important, that's not all you need to do. There’s a difference between getting over someone and wanting to get over someone. You need to get yourself to want to be over it before you will ever actually feel it. Wanting to get over someone takes time, thinking, and probably lots of tears, but it’s the only way to get over someone in a healthy way. You will know when you reach that stage.
The first thing to remember is that it’s normal to be sad. You always seem to reflect on all the good times. You’re going to be use to talking to them at certain times of the day. If you’re not ready to go out with your friends, wait until you are. Rather than forcing feelings on yourself, accept how you feel and try to put a positive spin on it. You obviously had something special if you feel this way.
The hardest part is knowing you’re ready to get over them. While following the normal ‘getting over someone’ routine of going out alot and talking to them less, take some time to reflect on how you actually feel on the inside. If you still wish that it was them talking to you instead of a stranger at a bar, or it was them walking with you in the mall making you laugh instead of your friends, could mean that you’re not ready to move on. You have to want to get over someone before you can. Wanting to get over someone doesn’t happen overnight and it may take an experience to get the feeling. You can still love the person and what you had, but you need to learn to love what you can have. Living based on the past slows you down.