Do guys care when they break a girls heart?

I am completely and utterly heartbroken by this guy. We were together for almost a year, and from the beginning I knew he wouldn't want me anymore one day, but I wasn't prepared for it yet. He means so much to me...I miss him so much, I miss what we had. I can't eat (totally lost my appetite) can't sleep (my heart literally hurts too much) and I cry a lot. He would tell me a lot I meant the world to him, and I'm pretty sure he meant it...he's a pretty sincere guy. I had liked him for years before he finally returned the feelings and I was so happy. Now what we had is gone, and I'm a mess. Do most guys care if their girlfriend or someone they used to be with feels like this? Just curious...