Heart palpitations

Hi guys so I just found this sr via a google search and I’ve been having symptoms that are kinda concerning me lately. It started about a week ago when I started drinking a Red Bull and got palpitations about halfway thru the can. Normally I’m fine with caffeine, but this was my sign to stop for the day. The next day I didn’t have any, and then the third day I literally had a couple sips and the palpitations were back. I stopped drinking it, but the palpitations didn’t go away (I tried protein, iron, sugar, salt, tea, water, deep breathing, showering). It’s been kind of a fluttering sensation in like my throat almost, and my hearts skipped a couple beats here and there. I’m ngl I’ve had caffeine in small amounts since, but I’m still nervous. I’m just wondering if this is like a semi-normal thing with POTS. I took an ECG on my Apple Watch and it came back normal so I think it might be psychosomatic, or just so subtle it’s not detectable. My cardiologist said my heart is fine (I had a holter monitor test) and I haven’t really gotten severe symptoms lately. It is finals week and I’m under a lot of stress/pressure, plus the anxiety over the palpitations only makes matters worse. I guess I’m just looking for some rationalization here or something to help calm me down and not make me freak out even more over this. Also, is there anything I should try doing to get them to go away? Any help or just feedback is appreciated :)