TTC and being patient? Need advice

So my husband and I have been together on and off for 13 years. We split about 6 years ago and had children with other people. We are now married for 3 months and I got my mirena out a month before that. The heart break of this is though the mother of his child gave his daughter shaken baby syndrome and she is no longer with us. My question is how do you be patient? How do you deal with the heart break every time your late but still get BFN? And how do you not get so disappointed your self and actually want to keep trying? These questions stem from the fact I was a week late and to finally started today. Just a little insight please.