Fighting Myself

So this morning I woke at 2:30 AM wide-eyed.  As I was lying in bed I started to psychoanalyze - never a smart idea in the wee hours of the morning when you're fighting insomnia - and realized how much more thin, fit, and healthy I was last summer.  I made much better food choices and was a beast when it came to working out.  Decided I need to get back on track so I came up with an eating plan and made the decision to start working out hard again today.  I even mentally picked out my exercise outfit - socks included.  Finally drifted back to sleep and now the sun is up and I am lying in bed trying to get motivated to exercise and I'm like...eh.  How can a few hours, some of which were spent sleeping, make such a difference in mindset?  And not in a good way.  Anyone else struggle with this?  Ugh!!!