Why I sometimes see two different versions of myself?

Sometimes when I look in the mirror or see photos of myself I see a fat giant headed freak with a low hanging double chin. Quite sluggish looking then sometimes I see a healthy looking strong jawed guy who looks like he's about one pump or a minute more of running until his body is considered athletic. I am aware that a stomach can bloat but can that effect the face. Sometimes I feel absolutely devastated by who I see in the mirror. It ruins my self esteem so bad.