Trying to have a baby makes me sad

We are trying to have our 2nd child and I feel like I am getting depressed. it took me awhile to get pregnant with our first (and I am truly thankful I was about to get pregnant- I know some couples try for much longer than we did or are never able to have biological children). Every month my period comes or only the one line on the pregnancy test shows up gets me so sad to the point I feel almost depressed.

We do everything right... and still nothing.

I know it takes time but it is hard waiting and waiting.

I am trying to take this time to love on my little baby while it is just her and give her all the attention I can.