Tim, I shall hazard a guess that this holiday is about a decapitated person called “Valentine” He was sainted and given this holiday. Others brought in the Greek God Eros into it and Cupid then was added.
You should read the wiki about Valentine’s day here: http://en.wikipedia.org/wiki/Valentine's_Day
How about seeing it as SELF-Love? You really have to love and value yourself before expecting anyone else to do this for you. We as a species do have two purposes in this life. To teach and to learn.
I do hope you will feel better and more valued as the days go on, perhaps next year having a companion, or…in fact… being OK with it if you do not. Not having a companion in no way devalues you as a person, no one has the power to do that, except you, yourself.
Here, we all have a common bond, and I hope you come to see the value of yourself and those around you. Let not diabetes or the lack of a companion decide this for you.