When I was pregnant with my second child I was still nursing my first child. When she nursed I felt like my skin was crawling, and like everything in me just wanted to make her stop, to the point my toes were curling under, I was biting my nails/my fingers. I had to breathe deeply and mentally talk myself through it being okay so that I didn't show my frustration to my baby girl.
I hated it. It made something (breastfeeding) that I cherished and was a bonding time for my baby and I, into something I dreaded doing. I tried everything to distract myself and keep my mind off of nursing, but nothing made it go away. It was getting worse by the day, but I was determined to nurse her, and wanted to tandem nurse once our son was born.
However, when she was 16 months old she weaned herself because she didn't like the taste of my colostrum that was coming in. Now I am not pregnant and have not had any signs of nursing aversion with my 4 month old.