I had exactly same issues with DD1. She was 2.6kg as well. I used to strip her off so she wasn't all warm and snuggly, i would tickle her feet and sometimes use a wet flannel on her to keep her awake. Feeding took 45 mins each side in the beginning and I had to wake her every feed. It was exhausting but it did improve and we got there in the end. It was just slow to begin with.