well i think you need to move on with your life, if you have all this time on your hands to obsess about an ex girlfriend then you must have time to fill it with something more constructive. and dont tell me there is nothing constructive to fill your time with

, i knew a person once who seemed very depressed and they joined the volunteer fire dept. and now they feel more in charge of their life (and there are hospitals, animal shelters, nursing homes...the list is endless) of places who need volunteers...
and you need to stop criticizing yourself....did you know it takes 17 compliments to delete one criticizm?
and on the days when you are upbeat what makes you that way? incorporate that into the days that are not so upbeat...good luck...