Oh yes... Do you have any family closeby? I found when DD was at her peak of unsettled-ness (3-5mo... ah, who am I kidding? Until she was about 7mo, lol) my parents' house was a safe haven. They didn't care if she cried - they loved her and didn't have to live with her. So, I could hand her over, know she was safe and have a break...
But even getting out for a bit, perhaps to the shops or a park where there're seats in case you find yourself feeling a bit wobbly, can do wonders. All the best to you - I really feel for you. It is so hard sometimes.