Tone and Mood

My rather somber disposition left many confused as to why my behaviour was altered. Was it due to the draining life of school? The lack of validation? My severe, mentally damaging view of failure? Yikes, this is a dour topic! I wonder how the reader felt about that, which is what I was practicing. If one could appropriately assume by the title, I was given the honour of learning about tone and mood. I have a general understanding, I suppose, but I could definitely use some assistance regarding tone; it does not seem to be different to mood at all, which affects my perception of it. The definition of tone seems too... simple, and I cannot wrap my head around it. I hope Tuesday bears better fruit. Not sour ones, though, those are not desirable.