what about a plan C? they move out now...because it is time they leave the nest...and then, if it works out you can still go to therapy.
how old are they? are they paying rent? are they paying for maid service?
if they are being taken care of and coddled and enabled then the household is dysfunctional and unhealthy for everyone concerned because it isn't fair for you to be in that role, it is unhealthy for you and for them too!
it's time for a change to stir up the dust!