It has been hijacked but so have Birthdays, Christmas, Easter etc. Its a celebration of love and as you are lucky to have your special someone, celebrate it with her. You don't need to contribute to commercialisation to do that. My daughters haven't found their special someone but do like Valentines Day. There has been disappointment for them sometimes but they still look forward to it.
It all depends on your mentality towards these things. Some people hate it, some like it, some are somewhere in between.
I just think it's too commercial, even more so than Christmas or a birthday.