Never really had a girlfriend and I'm only getting into somewhat decent shape now. As such, I've got a lot of emotional desires, mostly ideas, that I've never really had a chance to fulfill. As such I find myself way too often (maybe once a month) falling and getting feelings for a random cool chick I happen to meet but can't close out on. This sort of leads to a brief spiral of anger/sadness for letting her get away, followed by more anger/sadness for letting me get those first feelings in the first place.

Any advice I can get for not letting this bullshit get to me in the first place? It gets to me and affects my diet and exercise routines.

EDIT: I forgot to include any info about me. I'm 25 years old. I work doing computer programming that I got a bachelor's degree for. I'm 5'6, currently about 160 lbs and have been losing weight (my worst was around 220 a few years ago). Currently live alone in my own apartment. Also I have a genuine baby face. Constantly get told I look like I'm 20 years old and can't grow a solid beard to fix that.