What Really Was It That Made My Heart Panicked?

woken up from a weird dream.
my heart was pounding and my lungs were trying to catch air.
i was breathing heavily.
i reached for my phone to check the time, 02:09;
my usual waking hour at dawn.

i messaged a friend whom I wasn't able to reply before sleeping
and was told to get up, put some make up on,
shake up and to not leave the keys on the table.
nonsense.
i'd rather get back to sleep than make the effort of going out.

the scenes were so vivid then.

i can still remember how i blew air on the pad of my thumb

to settle my disturbed heartbeat

and how i told myself to not forget

the sequence of the scenarios

for I will write about it the soonest am fully awake.

and now here i am, trying to recall everything

but all i could muster were the vague settings;

came from a job interview,

chatted with friends on a boardwalk and the waters;

the vast body of water which i forgot

if i was in it swimming, floating or drowning.

What really was it that made my heart panicked?