Evening fussiness

Hi girls, my 6W old has fussy evening for over 3 weeks now. Each day, before he sleeps for the night (waking for feedings every 2-3h) he goes for 4-5h with no sleeping. I just read, that a 6 week old should only go for up to 2h awake at a time, so we must be doing something wrong, yet no matter what we do, he needs those few hours awake each day. (at one time he slept through the evening and then had his 4h from midnight till 4am).