2am feeding

Hey ladies. My 5 month old is struggling to sleep at night lately. We feed at 8p then bed. Was doing 11pm feed also but stopped waking up bc seems to make her more wired. Today just let her sleep until she woke a 2am to feed: . (Formula fed) my question is how long do u have to burp/keep baby upright at this time. Everyone’s telling me I don’t need to burp as much anymore but I still do. Mama is just exhausted looking for some advice. Thank u!