Many girls find this time of year difficult for many reasons, especially if they are disappointed that they're not sharing it with a man they love.
But, being philosophical and accepting where you are now is truly transformational. Look at your life as a scared journey with a higher purpose. Each moment is an opportunity for you to grow and strive to be a better version of yourself. Understand that there is a reason why you're still single and it hasn't anything to do with you not being good enough or being unworthy.
If you want to simplify it a little, think of it this way. Take a step back for a minute and imagine the man of your dreams. You don't know who he is or where he is. He may be in a relationship right now, that's coming to an end and he needs time clear it and prepare himself for you, or he could be in another part of the world, soon to move close to where you are, or he may be so caught up with work that he hasn't had time to look up and find you yet. Whatever his situation is, he hasn't found you yet either, but he's coming... Also, you may not be ready yet. You may have some things that you need to do in order to be ready for him too, things that you may not even realise until later on, when you look back.
In the meantime, you want to work on yourself so that the moment he lays eyes on