I find saying, "Thought thought thought" in your head helps me become more aware of my thoughts, so I realize it's just me overthinking. When I physically feel anxious, I'll just repeat "inhale the good, exhale the bad". Then I'll inhale threw my nose, and exhale through my mouth become more relaxed. There's also box breathing(inhale 5 seconds, hold 5, exhale 5, hold 5 and repeat a few times), there's also the 4,7,8 method. Which is inhale 4 second, hold 7, exhale 8 and repeat a few times (all of them inhale threw nose and exhale threw mouth) Structured very chaotically, but hope what helps me will also help you.