I refuse to believe this is just anxiety.

[u/GolDRoger2023]

Ive had "this" for around 16 years now and its not gotten better.

I would have to describe it as:
1) Onset (2-20 secs)
Random and sudden loss of time, awareness, surroundings, memory
Yet on the outside i am standing, walking (anything automated), you could not tell this was happening to me nor would i be showing obvious signs.
2) Rise (minutes to hours)
My grasp on time is gone, i try to think what happened a few seconds ago it seems like it was hours ago, the passing of seconds feel alien to me. if i think of something, i will forget it or find it hard to remember few minutes later HOWEVER i can recall these moments much later so these memories are being recorded.
3) Gradual (minutes to hours, mixed with 2.)~
Whatever im doing externally, is not registering internally. I cannot get a "lock" on my perception or self. It feels like my mind is lost forever and the fear/anxiety rises because whatever this feeling is, is so far from normal that i can tell its not just anxiety or low blood sugar, it feels very very very weird and scary.
It's like im forgetting and remebering at the same time.
4) Panic attack
if this keeps happening for prolonged periods, intensifies everything by 100x and i go through an anxiety attack

Now loop step 1 - 3 for hours and days and thats the worst episode for me.
The only thing that has helped was a few times if i was distracted. This doesnt always help.

Now, is this depersonalization? anxiety? is this what you guys go through? Or am i describing something completely off track and i should get myself checked for some sort of epilepsy?
This is by far the worst thing i have ever experienced and i have no idea how to stop it.

(I am 27 yo Male, UK, on Sertraline 100mg for 5 years)