The "positive thinking" movement has a long history, and make no mistake, I'm a big fan of positive thinking just like I'm a big fan of a sunny fall day. But just like sunny fall days in Texas, an endless stream of positive thoughts isn't the norm for most people. Especially if you have an anxiety or stress! For people with stress and anxiety, positive thinking can feel like swimming upstream. And well-meaning family and friends will often say "think positively" or "look on the bright side" when trying to calm their anxious loved one. This all leads to judgement and an implication that you can just think your way out of an anxiety disorder, which anyone whose dealt with anxiety for long knows: that just ain't true. Further, positive thinking can make anxious people more stressed because all these positive statements make a person feel like they're lying to themselves or being lied to. (Imagine a time when someone gave you a false compliment and you knew it. You no doubt ended up feeling more resentful than warm and fuzzy!)
However! Positive thinking can be helpful in the throes of panic and stress, if 1.) it is done right and 2.) you include positive statements that you can conceive of to be true. Notice that I said conceive of, not 100% believe. In other words, construct positive statements that have the possibility of validity. For example, in the middle of a panic attack, it's probably not helpful to say "I am calm" because you clearly are not. But what about "I can calm down"? It may sound like a silly distinction but our words are powerful. In fact, it's often words or repeated thoughts that propel our anxiety out of control, so it's not a big leap to suggest that choosing our words wisely can help calm anxiety or panic.
Notice next time you're in the middle of a panic: what do you say to yourself? Often it is things like "I'm losing control" or "This can't happen" or "I'm so upset" or "I can't calm down." Sound familiar? Try replacing those thoughts. Don't fight the ones that are there, but try inserting more empowering ones. But empowering yourself and talking positively does not mean lying to yourself. It just means being open to other possibilities. And "I can calm down" is, luckily, a possibility for all of us.
For more practical tips and how to treat anxiety naturally, speaking to an anxiety therapist can help you stop anxiety and all that negative talk in its tracks.