If it were me, I would avoid adding any solids at 14wo. Are you taking blessed thistle/fenugreek now rather than the domperidone? Did you come off the domperidone suddenly?
The suggestion of compressions is great, totally agree with that. If you're needing to up supply, make sure you're feeding frequently (or at least doing some pumping after you've finished nursing), make sure you're getting adequate fluids, nutrition and rest and keep going with the supplements for now (and, easier said than done, try not to stress).
FWIW, LOs will often take more from a bottle top up at 1) it's easier to get out and 2) they don't get the "full" signal as soon as they would if they were feeding directly from the breast.
Sounds like you've had a bit of an interesting journey so far, but you are doing a GREAT job.