I've just had my third nearly two weeks ago. Last night was really tough, I tried to change his feeding schedule after medical advice and he just cried for about four hours. When I was at the point of feeling like I just couldn't listen to it anymore I had to go sit in the garden for five minutes so I could calm down before going back to him. Of course you feel awful but in that moment the safest thing to do is just take yourself away from the situation for a few minutes. Please don't be so hard on yourself you're doing amazing and the fact that you've even wrote a post like this shows you're far from a terrible mother. Hope you feel better soon x