It sounds very similiar to my girl Heidi (14) I lost her last year..I know what you mean when you say you felt physical pain..my chest was heavy for days.
It DOES get better with time..i still feel very sad when i think of my girl..she was with me for 14 long years and i am so very grateful for that..i have pictures of her all over the house. I now have my little baby girl Pixie, and she is the joy of my life..i cherish her and i hope to god that i will have 14 or more years with her too.
hugs to you..pm me anytime.
Kerry & Pixie.