This one really spoke to me, I know this feeling all to well.
The opening verse is strong and drew me in with the line keeping my tears in a bottle, how many of us do this??? It is interesting that you put them on the window sill where the sun shines, it is like you are hoping the sun will dry them up and make them disappear? Turn them into sunshine and happiness?
The middle stanza is so powerful because you can sense the hoplessness that you feel, you feel hopeful of something and believe in hope, then it gets taken away and you feel betrayed like it has lied to you, and you feel anger at yourself for believing it in the first place.
The ending is curious because for you we may not know who this person is, but for the reader we all have this person who holds us back, whither it be ourselves or someone else, we have all had them in our lives.