Anyone else have a similar experience?

So last night, I woke up because I needed to cough -- just for the record I don't have colds at the moment. So I coughed and turned to my right side (I was lying down), and I could feel a bit of phlegm rise up in my throat a little bit.

All of a sudden, a cold surge wen through my body and I started palpitating. I stood up, went to the bathroom to pee (but also had a sudden urge to go number 2, which I did), and all the while I was practicing breathing in 4 seconds breathe-4 seconds hold-4 seconds exhale - 4 seconds hold. My heart started to normalize after about a minute or two. So I decided to try to lie down, and there it was again -- I started palpitating again, I felt like my heart was racing a million miles per hour. I stood up, put my hand over my heart and started breathing again -- I thought I was going to pass out. Eventually I started to go back to regular heartbeats and I was able to find a way to fall asleep again. Now that I'm awake, I'm freaked out about what happened.

The thing is, I could breathe in deeply, my chest wasn't in pain -- it was more of my back. There was no blurry vision or anything like that. So I'm wondering if this might be a panic attack or anxiety attack. I've had a panic attack before and it also felt like I was going to pass out. I felt like I was lacking in oxygen and I felt like my heart wasn't beating properly.

Has anyone ever felt the same before a panic / anxiety attack?