My ex and I split up 6 months ago and I just can't move on. He is with another girl who I hate!! She is not right for him and I was wrong to break up with him. I don't know what I was thinking. It's one of those, 'You don't know what you've got till it's gone' moments. But I don't know what to do. I can't get up in the morning without feeling ill because I can't bear that he is with this girl and not with me. What can I do?