Starting to give up....

Stepheney
So I have 2 healthy boys 5 and 3 years old. I lost another baby boy in 01/16/2015 due to his umbilical cord getting wrapped around his neck at 24 weeks. I got on the birth control shot until August of 2015 and then switched to a pill until February of 2016. I took the morning after pill one time in February after getting off because I was afraid I wasn't ready. Well after that we have been trying non stop. I take prenatal vitamins and track my ovulation and fertal days. Still nothing.. 
I'm getting so discouraged and upset.. I'm in need of some advice encouraging words or anything please..