Breakups suck, but you are not the first to feel this way. Be glad that at least you are in good company.
It takes time to get over someone. You can try to busy yourself with work or play, and that's cool; just avoid anything self-destructive. Surround yourself with friends or family. Spend time with friends. These are short term things that'll help ease your sadness, but I'll admit, they aren't solutions for the long run.
What do you need to do in the long run? You need to realize that perhaps if you couldn't deal with your family, then maybe you just weren't ready for this sort of relationship. What exactly did your sister do? Sometimes family and friends can see things that we (as biased parties) can't see. Or sometimes, families aren't too understanding of our sexual orientations or choices of partner. That takes a lot of talking to get through.
As for things like talking about kids and raising families, I have to say, a big mistake a lot of people make is that they jump the gun. they date for a whopping 6 weeks and are already picking out the china patterns. Which is not to say some folks have successful whirlwind romances, but that a lot of people move too fast, get too involved and when things end, wind up having a lot of things crash down on them. Sorry it happened to you, but it's not the end of the world. You can find love again if you want to. you just need some time to figure out what you want, how you're going to get what you want, and how you're going to handle things next tie around.
Universal Law #4721: Any joke can be made funnier with the word "goatf**ker." Corollary, any story can be made more entertaining by adding a few ninjas.