Fertility – What if I don’t end up having kids?

Me and my husband have been trying to conceive for a little while now. My hormones are off and I am currently in treatment. Of course there are no guarantees. I have worked to be not so attached to the outcome of the treatment. When I check in with myself though, I realize that I feel unattached right now because deep inside I assume that it will work someday and we will have a child. There are times though when that floor is not there and my thoughts are: “What if it doesn’t work and we don’t end up having kids?” When that happens, I cry and I feel frightened. I don’t even let my mind go there. Do I make peace with the worst case scenario? Or do I stay optimistic that it will work, given the placebo effect?