my sleep schedule is totally messed up

[Altruist]

It's very pleasant to be up at 3AM

To still have a normal sleep schedule, just go to bed slightly earlier than 8, or alternatively "start a new day" without sleeping (When 7-8 am comes, fix some breakfast and wear new clothes).

been trying to do that for years while studying, always returned to my old habits within 2-3 days

it doesn't solve the core problem, which is usually doing jack shit the entire day and just rotting for neets