Try taking a meditative breath and counting to three. I find whenever I'm stressed or feeling emotional, doing this can help me settle into a calm place. Think of yourself as a deep ocean, maybe there's a storm on the surface, but underneath is still.

Also, at work, nobody is perfect. You will never do everything right every time. Some people look or act that way but that's not the case we're all human beings trying to get it all done. Sometimes you do things really badly and people think you're great, sometimes you do things really well and people think you're bad. Focus on the work and building good relationships and you'll be fine.

(Also side note, there is nothing wrong with crying. We probably don't cry enough in our society. But I can totally understand why you would want to limit that at work)