Do I have Narcolepsy? Talk to for this?

I feel a sleepy the whole day even after having 6-8 hours of proper sleep I dont crash sleep or anything but I still can't focus properly, My eyes feel sleepy all the time, I should point out that my fitness tracker says that my deep sleep time is not more than 30-45 minutes. I am getting worried sir, I sleep around 8 and I wake up around 4 am. After that I take my pre workout it has about 180-200mg caffeine Is it bad ? I mean its still under the daily caffeine intake bracket right? Is that hurting my sleep? I study 4am-8am in the morning and I need to be on full alert at that time, what do you advise sir? Should I should taking the preworkout? If yes then how can I be alert the whole day ? Also, how can I improve my sleep ? Please tell me what kind of doctor I should talk to for this ?