Congratulations for your good time in your first marathon! Not bad at all being the first.
Marathon is a very difficult discipline in athletics. It is tough, very tough and you have to be very well trained physically but also mentally. My best time in Marathon is 2h54" but I was preparing 2h45"... my problem was that I didn't rest properly the week before... I did a half marathosn in 1h 22 minutes as a training the sunday before the marathon and I paid afterwards during the 42Km.
Marathon is another world indeed and every time you run it you can learn a lot of things about yourself.
Keep on running and posting good races!!!