My youngest son constantly made faces for the camera when he was little. So much so that as I was making his "This is Your Life" video for his high school graduation the theme for it became apparent early on since every video of his growing up years showed him making a face. I often said he was given to us for our old age (I was 38 and my husband 42 when he was born)--the son that would keep us feeling young.
Loretta suggests we should keep a Groucho Marx glasses and nose/mustache handy to don when we're really feeling stressed. I can picture my family coming into the kitchen and seeing me standing at the stove wearing such a get-up. That would surely break any tension in the room, don't you think? Her other suggestions are: look in the mirror and ask yourself, "How serious is this?"; do something nice when someone least expects it; write down your favorite profanities and assign them a number, then when someone gets on your nerves just say the number; adopt an attitude of playfulness--keep your mind open to silly, irreverent, iconoclastic thoughts; and lastly, a sense of humor sees the fun in everyday things.
That last one sent me to the Internet to look for sense of humor tests. Just Google "sense of humor" and see what you find. You may find you need work on yours. This might solve all your problems. ☺ Be sure to let me know if you try one of the above suggestions and what happened.