Trying 3 years now

Me an my husband have been trying for 3 years now for baby number 2 last april he got diagnose wit cancer stage 4 he now is in remission they told us it was safe to get pregnant but we have no luck were at the point where we fight none stop because I can't pregnant again an I can't take it anymore I see friends an family having babies an it's breaking us apart what can I do to keep us from fighting about this???