Mine was like yrs last time....
8pm-12am - this timing is ok, keep it. If you can, sleep with him together. Called co-sleeping. you gotta adjust yr daytime schedules - like finish all household chores earlier etc. you got to do that or you will end up sleep deprived.
(Unless you wanna wake him up during 10pm for a feed? So that logically they fall into deep sleep during 10pm till 2am? But i thought 10pm for a baby to sleep is a bit too late?)
12am - feed, slowly increase the amount, perhaps 10ml?
2am & 4am (see which slot you can try on, either one, one is hunger, the other may be caused by sleep cycle) - Try to pat him back to sleep....actually babies wake up becoz they do not know how to fall asleep themselves, not really of hunger. If you read up the sleep cycle, babies will fall into deep sleep, light sleep, then deep sleep...etc....it goes in a cycle. that is IF you can, its ok if it doesnt work out. Dont force yrself and stress it even further.
I must say its easier said then done...anyway babies will outgrow this stage soon, maybe around 4-5months? They will wake up in 3-4 hours intervals...at least longer. Around 10months my boy was sleeping thru the night but sometimes will wake up during 3am for night feed . So still ok.
so the ideal situation for you now is to co-sleep....you follow your baby's sleep times.