my ex is NOT who I thought he was....

my SO and I had been together for seven months, and everything has been perfect other than a couple fights here and there, like every couple has.... so two weeks ago, we started fighting a lot more because he was out "shopping" for me for my birthday but his stories kept not adding up.. so finally two days after my birthday, he left me because of the fights... he just told me he needed time... come to find out, he's been talking to someone from his job for a minute now... and he has just completely changed... he doesnt care about anything anymore, I was in the hospital the other day and the only thing I wanted was for him to be there, and he said he was coming, but never showed up... he wont even see his son.... his son's mom let me have him for the day, and he just keeps asking where his dad is, and saying he misses him... my heart is soo broken right now, because I loved this man so much, and he was someone completely different the entire time... and now my heart is broken even more for his son, because he just doesnt even care.....