Expressing your emotions is indeed difficult. In my case, I only have my words and actions, which suffice most of the time.
The real problem for me is that I cannot always see what emotions others are expressing unless it's clear.
So... I'm having a tough time figuring out most of the emotions that went into this improvisation. Maybe if I knew more about what the various tones, paces or transitions meant in music, I could figure out them better.
Nonetheless, this piece is nice to listen to. I get the feeling you really like the friend you made it for. Am I mistaken if the music even sounds grateful at some points?