Bumpy road

Just venting and looking for encouragement.... So much stuff going on right now. I'm 38, we have a 3yo son, two miscarriages since July 2017. Really want number two. My fiancée was diagnosed with thyroid cancer (good prognosis) and recently had some very extensive surgery to remove 53 lymph-nodes. My focus is on providing him and my son with all the support they need, but I feel the anxiety building up in me because of the lost time. Can't help but feel this is the end of the road, though I know that's not necessarily a rational thought.