All of a sudden feel down and sad

So I currently been trying to conceive baby #2 and I found out my boyfriend cousin is pregnant with twins. When I found out she was pregnant I just randomly got emotional and somewhat depressed. I don’t know why but this is how I felt when my sister told me she www pregnant before I found out I was pregnant with my first child. Is it a bad thing that I feel this way . I nist been trying and been stressed lately and I been trying so hard to get pregnant .like I feel like crying. I don’t know what to do because it’s so hard not to think about getting pregnant because my daughter is going to be 1 in a month . What should I do