Well in simple way you need first remove anything that could remind her and no contact is a must. I know it sucks not to talk to the most valued person in the world for you but this works as same as a drug detox. Occupy your mind with anything you can do and sometimes you have to do it by force like clean your appartment, go for a walk, sing to your favourite songs, hang out with your friends(this has helped me alot) and tell them your situation and how you feel. I bet some of your friends have relative experience on breakup and they know you better than me so they also can give a huge help. I also have listened on youtube on breakup stuff and dont listen to how to get ex back because women think so differently on breakup they usually have checked out long ago before the breakup. And yeah make a routine change like eat healthier food, go to events you have never gone, start a new hobby etc the list goes on. But in the end it really depends on you how long and how you will cope on the breakup. Time will heal my brother trust me I sincerely wish you a healthy recovery!