What is the difference between I try not to stress out. and I try not to be stressed out. and I try not to stress. and I try to lighten up. ?Feel free to just provide example sentences.

"I try not to stress out" 👍

"I try not to be stressed out" --> "I try not to get stressed out." 👍 (It's a little more natural.)

"I try not to stress (about something)." 👍 (Usually you have an object, something you stress about.)
"I try not to stress about interviews." 👍


"I try to lighten up" means something a little different. It means that you try not to take something so seriously. Sometimes one of your friends won't smile or laugh, and they don't want to talk. Then you might say, "You should lighten up."

"Whenever I realize I'm in a bad mood, I do my best to lighten myself up."

(Notice that you can "lighten up", but it's usually more clear to say "lighten myself up".)