I'm very sick to my stomach....how do i make myself throw up?

i havent eaten many rich foods at all in the past few months, and i did today (happy father's day...lol) anywayz im sooooo sick to my stomach but i cant throwup :( i tried putting a finger down my throat but it never works for me. i drank a very tall gl of water but that didnt make me puke eaither. please help me - i have no gag reflex whatsoever and my stomach fells terrible.