have you tried a triangle pillow ? i found that helped me feed, though in cradle hold, but i sometimes didn't even have to hold? ITMS. i just attached bub and let the pillow do the work!
have you tried lying down too? not sure how practical it would be during the day with the other munchkins, but perhaps early morning and evening/night?
hope that helps
and good work on the feeding!
x madame x