Hi, I'd like to help you with your question.
It sounds like you are finding that your grief over the loss of your relationship is interfering in your day to day life and you are trying to cope with it.
It is very normal to experience grief over the loss of a relationship for up to 6 to 9 months. Any loss of a relationship is going to cause grief, which you have to work through in order to move on. Part of the issue here may be your feelings about the relationship. It sounds like it meant a lot to you. If it did, it will be more difficult to overcome. But you can do it.
First, recognize that it is ok to feel angry, sad, frustrated and confused. You have gone through a bad experience. You shared a lot with this person and now they are gone. You are going to experience a range of emotions until you feel better.
Second, be good to yourself. You need a break. Get out of town for a few days, hang out with friends, take some time to do something different. Back off some of your normal activities and take a break. You need to allow yourself to heal.
Third, allow yourself to grieve. Talk to close friends, family or others who can help you. Write out how you feel. Write a letter to your ex telling her about your feelings. Don't send the letter but keep it so you can add to it or burn it, whatever you feel.
Four, remember this is grief. It takes time. But you still have your future. And you will have other relationships. You will smile and be happy again.
Let me know if I can help any further,