Hi. I Just Got Out Of The Pool About A

Hi. I just got out of the pool about a half hour ago with a stomach ache which isn’t unusual. Shortly after I began getting shaky. I’m monitoring my heart rate on a Fitbit and it’s going from around 90 to 70 repeatedly. I also have anxiety which could be a factor in this. Should I be worried? What should I do? I am a 15 year old girl