I made something similar to this[0] a few years ago for my own use (except I would record my mood every hour). Honestly, using it ended up making me sadder - most of the time you feel "meh" (5/10) and seeing that quantitatively can really dishearten you. In fact, my average monthly mood fell from around a 6.3 to a 5.8 while using it, with no other major changes in my life.
Well, given that people tend to perceive swings in things rather than absolute values of things, wouldn't you expect to feel 'normal' unless things are getting noticeably better or worse at that point? And given the coarse granularity of the inputs, a drop of 0.5 seems well within what you'd expect just from random noise.
[0]: https://frank.salmick.com/indexfiles/images/full/mood.jpg - the red line is stress level and green line is mood