How do you know when your relationship isn't working anymore

I been with my other half for 6 years and I feel like we are falling apart iam trying so hard to fix our relationship but I don't know if he even wants to fight for what we have i feel like he maybe just waiting for me to end things we have a son together and live together these past few days have been really hard i feel like everything I say is wrong and he just won't talk to me anymore I try to talk to him but sometimes he doesn't even answer me back I feel really confused and my anxiety is through the roof how do you know when your other half has given up ?