For your phrase I'd say "Momak koji raznosi picu (or even better: dostavljač pice") je već trebalo da bude tu (ovde) sa picom koju smo naručili. On kasni! (a mi umiremo od gladi) "
to starving - umirati od gladi
by now can be : " do sad" and we use it when we do not have patience any more to wait for someone/something. Also, we can use "već - already" to show our impatience.
For example:
Hoćeš li mi već više dati svoj broj telefona? - Would you alredy give me your phone number?
Gde si do sada, zaboga? - Where are you by now, for the God's sake?
If you have any further questions, feel free to ask me.
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