How can I cope with the fact that my partner left me for my best friend?

Wow. I am so sorry that your ex boyfriend hurt you in that way. It's very harsh. There isn't really much people can say to make you feel ok. Because the fact is you are definitely going to cry and feel sad. That is a part of you getting over it. Some days will be better then others. Just realize that it is not your fault, and maybe it just wasn't meant to be. That doesn't show very good character on either of their parts to do what they've done to you. Basically you were betrayed in the worse way. If I were you I would try to busy myself with either work or school, surround yourself with positive people like your friends and family and just focus on bettering yourself and enjoying your life. This is not the end for you even though it may feel that way. Time heals all wounds. Just take it one day at a time.

Hello, I am sorry you are going through this bad experience at the moment, and it must be devastating for you to find this out, but you are not the only one struggling through this and there is help out there, visit http://www.getconnected.org.uk/ for support and 1 to 1 peer advice via telephone the number is free if you wish to call, or you can speak to them via chat or email, whichever you prefer. Maybe take some time out for yourself and keep a log diary of how you are feeling, going to the gym is also great for letting out some stress to! Just remember support and advice is always out there! you can gradually take steps into the right direction to help you through this situation, at your own pace and own time, no rush.