"separation anxiety"? doesn't quite cut it

I leave for work during the work day week, tearing myself away from my lovely boy. They call it "separation anxiety", such a clinical name. But what it feels like for me is a real heart wrenching, chest tightening, eye tearing, brain numbing pain that starts from the chest and spreads. And it dulls and quiets at work, until I get too busy to think about it, much like how one ignores a skull cracking migraine. Then at the end of the day as I approach my mum's place, my heart starts to expand and finally slowly when I first hug my son, then the pain of the day of being away starts to slowly ebb. I hear it all the time, "You'll get used to it", "It's better like that, there's no way you can manage him yourself" but really I didn't and now having returned to work for the last 12 months, it's gotten more poignant, if anything.