Valentine's day is probably one of the harder days for single people (who want to be in a relationship). In general as a single person there are only a handful of times a year where I feel lonely or feel it more strongly, my birthday, new years day and Valentines day to a certain extend. Like I said before it's not that I don't mind being single but one can't need easily swirch emotions on and off. It's best not to dwell too much on what you don't have but rather what you have.
I understand and sympathize. New years is never a problem for me luckily because me and my small group of geek friends decided a few years ago that we celebrate that together. None of us is especially lucky in the relationship area, but we never feel like we're missing something at New years at least
Regarding the single life, I do get what you're saying about the freedom of it. I like it as well, but at times it feels like I'd be willing to give up that freedom for someone to share it with. It's not as important as it used to be to me, but even so.