8 month old having a hard time breastfeeding

My son is 8 months. He has been EBF the entire time refusing to take a bottle. Well within the past 2 weeks he seems to be having a hard time breast feeding. I think it's the position. He's almost 25 pounds and almost 28 inches long (estimates as we haven't been to the doctor for his 8 month check up yet) and he doesn't fit on my Boppy pillow nicely anymore and the nursing position suggestions lactation consultants give you aren't working because of his sheer size. I know I have a great supply and We are not experiencing any thrush symptoms so I don't think it's that. A nyone have any suggestions for nursing him in a way where he could be more comfortable? Thank you in advance! I have included photos of him as well to try and show his size.