Separation anxiety

My grandmother asked to keep my baby for the weekend and I says yes now I'm so depressed because he's not here. He's 8 months old and this is the first And longest time he's been away from me. He was admitted into Woflson's children's hospital when he was two weeks old and I stayed with him the entire time. We have never been apart. Hire are some ways I can cope with this? PLEEEEEAAASSSEEE HEEEEELLLPPP MEEE!!!! I've been crying since he left.