Originally Posted by jordanbillie
Was this a 2/5 NL game? If so, buy in with $500 and make it more preflop.
Pretty much my thoughts. If you can't buy-in full to 2/5, drop down and play 1/2 with a full buy-in. Also, I know you said you were new to the table, but if multi-way pots have been the norm, you need to bet this bigger pre to thin the herd a little bit.
Your post-flop $20 bet is just spew. Its less than 1/4 PSB and with that many players it won't accomplish much. Against 3 other players you WILL get called by somebody. So, if you are going to bet the flop at all (highly questionable v. 3 opponents who all have position on you), you need to make your bet significantly bigger. Just realize that if you do this, you are essentially turning your hand into a bluff.
As for me, I hate to, but I'm against 3 opponents and out of position, I'm Check/calling a smallish flop bet and Check/folding to any significant betting.