Sadness

On December 19, I took a home pregnancy test. On January 19, I miscarried.
Sometimes, I am overwhelmed with sadness. It hits me suddenly and for no apparent reason. For the most part, I'm a very logical person and I know that there was nothing I could have done differently. But I think I had finally gotten past the shock and had started looking forward to having a new baby.
I have the two most amazing boys already and I never go a day without recognizing how lucky I am that they are so wonderful.
Physically, I'm weak. Emotionally, completely broken. So why do I feel like I SHOULD be stronger in both aspects? I know I need time to heal. I realize this isn't easy for anyone. But I also feel like I've cried myself empty. And then without prompting, it starts again.