I was on Zoladex for 3 years and had several side effects but lack of appetite, problem with dry food, fluid on lungs weren't among them. Tiredness certainly was plus muscle loss, bone aches, hot flushes, trouble sleeping, trouble staying awake, depression, weight gain, loss of body hair etc all expected and basically accepted.
As everyone says its impossible to say exactly what zoladex will do to us if something in particular is worrying - fluid on lungs - get in touch with his specialist nurse I'd say.
Peter