You raise two separate issues. The first is a breach of the implied warranty of habitability because the sink is unusable. Your landlord has the obligation to keep the house "tenantable." Tenantability includes providing you with plumbing facilities that are in good repair and that meet Code as of the time that the house was built or the kitchen installed. It is safe to say that the absence of a kitchen sink does not do that. But your landlord breaches the implied warranty of habitability only if the house is substantially untenantable.
You do not say how long you have been unable to use the sink. I do not think the nonworking sink during mold repairs is enough to render the unit substantially uninhabitable.
The other issue is a breach of contract. Your landlord promised to provide you with a sink and a dishwasher. By failing to provide them, he has breached the lease.
But that breach is not enough to enable you to withhold rent. You would instead have to take him to small claims court for your damages.
Your damages would not be very much. Again, much would depend on how long you were without a kitchen sink and dishwasher. Just because you do not have either does not mean you cannot use your kitchen or that you have to eat out for every meal. So your damages are just for your inconvenience of washing the dishes in the bathroom. How much is that worth to you?