I don't get the context so I'll try my best.
私達には少なくとも3日おめでたい日が\nあったんだけど、去年の春からは\nおめでたい日が1日増えた。 羊君の誕生日が増えたからだ
While we only have three birthdays to celebrate every year, at least it went up by 1 since last spring, since we've counted in 羊's.
授業が終わると同時に、\n錫也は私の席に来た。
Right as class ended, 錫也 came to where I was sitting at.
誕生日は散々悩みに悩んで、\n私達らしく屋上庭園で星を見ながら過ごす事にした。
We spent our time doing our usual stargazing on the rooftop garden as we brood over our birthday troubles.
それは、やっぱり女の子なら\n誰でも憧れる事……。
As I thought, it doesn't matter who, she'll yearn for anybody.
でも、羊君が仕事なら仕方ない
but when it comes to the job, 羊 can't help it.
私は、わがままをぎゅっと胸に仕舞い込んだ
I kept my selfishness at bay.
Don't trust my translations though. I'm very known to screw up with particles.