I can’t sit down!!! 3 days after birth..

I’m in so much pain.. I gave birth 3 days ago. I only have a second degree tear internally and a small graze on my labia. Had both stitched. I can’t sit properly 😔 I can’t just be comfortable and nurse my baby and it’s breaking my heart 😔 any tips or ideas on what to do? I’ve bought a doughnut pillow and tried that but it doesn’t help. Any one have any idea how long this pain will last ?? Please any advise would be great... it’s getting me down, I want to be enjoying my baby and my 2 year old daughter is finding it hard with the adjusting and I’m not able to be there for her properly... any advise would be great! Xx