My Lonely Son

Since my husband gets the master degree scholarship, we both know all the consequence, such as lack of time with family but my 2 year old son doesn’t. On his mind, it’s only Daddy is here and Daddy is not here, that’s what I thought! But when I was observing his behavior lately, I found out that something missing on him. He gets angry and sad easily, but those eyes are sparkling every time he sees his Dad at home. O my God, he misses his Dad a lot. It gives me a big hit as a mother. I know, I spend less time with him since his baby sister was born. I want to give more attention to him but in the other hand, the baby keeps crying and breastfeeding all the time. What should I do?