I'm sorry you're having a hard time. Possibly working too hard to "keep it together" is actually harming you. Sometimes (in my experience) it's best to find a place and just let it out.
I've actually written a hub or 2 on my experience with my stillborn, Brandon, and grieving.
It's difficult and it seems the birth of spring always gets to me too. It's the adrenalin in me as all these beautiful things start blooming and a sense of freshness in the air that reminds me of what is missing. Again, close to winter I go through the same feelings as things are dying away and seasonal depression seems to set in.
My advice is, give yourself permission to cry, be sad and it will pass faster than if you try to suppress it. If you need, find someone you can yell at that won't take it personally. Tell them why you need to do it. That has worked for me a couple time in the past.