Baby #3 help!

So I just just had it confirmed that I'm pregnant with baby #3. My oldest is about to be 3 (July 7) my second is only 7 months. I'm about to be 21(June 22). I've been freaking out pretty bad. My husband support any choice I make but his choice to to keep it. I'm just extremely freaking out and need a crap ton of support. How about you lady. How many kids do you have? How far apart are they in age? Am I the only one this this young with this many kids?