How do I pretend to be happy, when I just want to break down and cry?

My son is coming home soon for a visit before he heads out to South Korea. I’m already freaking out. I’ve been hoping that all this mess with South Korea would be resolved before he deploys. I’m terrified things will get worse and I may never see him again. I get we are not all guaranteed ever seeing love ones from one day to the next. But I go to bed at night pretty sure he will be fine till we meet again. But in less than 3 weeks he heads to SK and it’s getting too real for me. I don’t want him to worry about me but it’s getting harder to hide my fear, especially since stories about NK become worse and our President doesn’t seem to help the situation calm down.
Any advice would be appreciated.