feeling frustrated 😩

I don't know why but today has been such a stressful day. Every time I take a pregnancy test and I see the negative line it breaks my heart. We've tried everything and it's been almost three years and we still haven't gotten pregnant. Does any one have any advice? Or anything they did that work for them? We have a wonderful boy turning 5 in august. And he is asking for a baby brother 😔. I don't know what to tell him. 😭