This isn't even for mornings. I feel like I need to sleep throughout the day constantly even though I sleep 10 hours each night. I don't even feel buzzed on 400 mg, I just feel about 70% close to normal, or how I felt when I was in my 20's. I literally have been mistaken for a drunk person before and I don't even drink. I don't take caffeine pills often, only when I'm going out with friends so I don't seem like I'm on something and things don't seem like a dream lol
I know this is normal ageing and all, when you're a woman in your thirties but it annoys me how I'm constantly napping when I'm sleeping and not even doing anything. Sometimes you've just got to biohack
It sounds like you built up a tolerance and would benefit from quitting caffeine altogether. The first week or so will be a groggy hell, but once you adjust, your baseline will be much more alert.
I don't have caffeine often, it's only when I'm on outings.
How often do you go on outings? When did the symptoms generally start? Was it around a time you started taking caffeine or taking more of it than before? Are you on other psychoactive medications that could affect your brain?
Regardless, if you're taking such a large dose of caffeine even occasionally, it could drastically affect your adenosine receptors, and that's only going to cause tiredness, speech slurring, brain fog, etc to continue EVERY day until you've been without caffeine long enough for them to return to a baseline.
Personally, I'd suggest slowly decreasing your caffeine intake. Most people say "just quit taking it" but that can lead to some really annoying crash and withdrawal symptoms, so I'd say slowly reduce by maybe ~50mg per dose, each week or so, until you're around 100-200mg max on any given day. If it doesn't work out, you can always go back to your current caffeine intake, but if it does work out, you've just saved yourself a big headache and potential medical problems.
I can promise you, this is not a normal bodily reaction to have at your age, and you're already hitting the recommended safe human limit if you ever take 400mg. To be clear, I'm not here to judge you. Just like most other people here, I think we're all just quite concerned for your health and safety.