HamsterGrirl is soooooo right. You have been through a trauma, behaved with enormous courage, and if you don't feel like faking a cheerleader smile, it's understandable.

There is some research evidence that the act of smiling, even when we don't feel like it, does something to internal biochemistry that does make us feel better.

If it helps, smile and "act as if," but don't put too much pressure on yourself so it becomes another goal to criticize yourself about.