How old you are and what you FEEL inside are the things that count!
Every day is a blessing, but special days are even more important.
I'd splurge and go out and buy my favorite candy bar, and get myself into a PLACE I KNOW I'll enjoy it and then eat it! Small present to yourself....what used to be called a 'circe' -tho don't know why. I always viewed it as a little treat.
Sometimes it's those little things that are comforting. Go with that and get on with all the other life hassles.
Later, like on the weekend? Go celebrate as best you can with friends [even if it's over a cup of herbal tea or something] and just find ways to laugh. That is what can get us all thru it all...
You aren't selfish at all! Not at all! Never think that - wait till you hit 40 or worse! Then worry? But not NOW!
Hugs and fun in your future! - j 's