I'm pregnant again, but I'm so scared.

So today I've just found out I'm pregnant. I took a first response test as my period isn't due for another 5 days but I had an incline that I was, I started having vivid dreams, excess snot and mood swings.. exactly how my last pregnancy started out so I thought I'll do a test and there it was my BFP. So going by the first day of my last period I'm 2 weeks. Yayyy! 
I'm unbelievably happy, this time it happened naturally whereas my first baby, he was conceived using fertility medals as I have PCOS. We were trying just having fun. 
I'm so scared, my little baby is only 5 months old so there will only be 14 month between them both when this new baby comes along.. how do people do it? Two babies under 2? That's got to be hard. 
I also feel so guilty when I look at my baby as if they weren't enough and I had to get pregnant again, I hope they don't resent me.