Not the best day

So we've been taking a break for a couple of months and now I am starting the panicing again. The what if's ....and its already upsetting me. I just don't know what to do. I've lost 13 lbs. and feel great but I still can't stay pregnant. I am so lost right now. I really do want to be a Mother. I am not against adoption or other methods of having a baby. And my fear is that if we just keep trying we will miss the boat and never have a child. I just really don't know when to say enough is enough...I mean it's hard to stop when you are getting pregnant. I just wish I knew the reason that I can't stay preganat so that I could fix it.