When BF was going really badly for me in the early days with DD, my doula bought us a new Medela bottle, not sure if you've tried it. Basically it's teat is designed to be similar to a breast in the way that it has a little reservoir in it, and the baby has to suck to get the milk in there and then into their mouths, instead of normal bottles where it is right there and drips or flows. It's a bottle made for BF babies, maybe that will work for you? The other thing we did was cup feed, out of a medicine cup. It's not ideal, as they get the milk super fast with minimal effort, but maybe worth a shot at this point. I hope you can get your DS 'on the bottle' as your DH says