How do i know if letting go is the right answer

Obviously there’s things that have been going on for a while between us but that would be any normal relationship arguments fights and what not but lately I been feeling so numb and having trouble sleeping at night, sometimes I feel like we are together just so we won’t be alone and yes of course we love each other and we are trying for a family but all this going on I really don’t want to bring a life in when the connection between us feels like it’s dying.. I don’t know I always fight for us to talk and get through our arguments so we can stay together but when is it enough. I’m scared to end it because I’m going to lose him but at the same time would ending it be the best decision for the both of us.