You would have been winning easily had you just played 4... exd5
Never ever ever play off of traps (unless of course it is the best move and whether they fall for it or not you will be in the best position-- which is extremely rare! [a good example is legal's mate. in some cases if they don't fall for the trap you are still winning, but in some you just lose!])
Always assume your opponent is a Super-GM. Even if you may have won more speedily by playing the person, you may have also suffered a devastating loss if they played a good move (either by accident or on purpose!). Not to mention you will really only improve if you look for the absolute best move every time. When playing lower-rated players, even if you can pick off major pieces and win easily, look for a better move, there often are sneaky ones which work better.
The big mistake I noticed on my part was 4.. e5. What could I've done better? 4... exd5 ?