I’m sorry you are going through this. Its good that there are other poops apart from the jelly diarrhea.
What type of dewormer was he given?It’d be wisest to contact the vets again, because when a very young bun presents with diarrhea, coccidiosis should always be considered. Coccidia are intestinal parasites that need antibiotic treatment. The bun can also lose fluids very fast if there’s ample diarrhea, and that is of course very dangerous. Because he’s already been to see the vet, you could just call them and ask what they think.
You have been doing really great so far. It’s not at all easy to rear a rabbit this young. A bunny that loses its mum at the tender age of 2 weeks has an extra sensitive gut because he didn’t get to suckle for as long as he should. This mean his gut isn’t fully armed with the right type and amount of the important microorganisms that help the rabbit digest its food. You can give a probiotic, for example benebac, to help his gut bacteria. This would be a good idea also if your vet prescribes antibiotics for him.
Many healing-vibes for ((((Goddrick))))