Gokhale method and breastfeeding

I am a new mum and find most of the breastfeeding positions uncomfortable, especially over a period of time. Due too some difficulties regarding breastfeeding, Biological Nurturing specifically position was recommended to me. After some research I have found out, that it is mostly basing on reclined position with weight on one's sacrum. Generally, I feel strain in lumbar and upper thoracic spine and sometimes some weird pressure in sacrum. I guess having weak abdominal muscles post pregnancy and possibly DR, doesn't help. 

I would appreciate some views on BN and some possibly more back-friendly positions. 

With kind regards, 

Renata Pučnik