Hard time with 2 kids

We just had our daughter nearly 4 weeks ago and we have a three year old son. He is starting to act out some, basically screaming for attention. He doesn't seem jealous of her, but I feel guilty that he isn't getting as much attention as he did before. I'm feeling pretty overwhelmed, and my husband has been helpful, but we are exhausted trying to meet the needs of both kids. I've been pretty weepy when things aren't going well. For those that have been there... when does it get easier?