Welcome to e health forum.
It seems that the description of fluid within your kidney and very low remaining function in the affected kidney indicates the possibility of polycystic kidney disease.
Unilateral multicystic kidneys is characterized by the replacement of part or the entire kidney by irregularly lobulated cystic masses (size varying from 1-30 mm) ,held together by loose connective tissue. The renal structure is completely absent, with scanty normal renal tissue.
In most cases the other kidney is normal and grows larger than a normal kidney to make up for the defective kidney, as shown by the renal function of 64%.
There is no need to be concerned about the effects of the condition. But monitoring the onset of issues like proteinuria, elevated blood pressure and change in renal functions should be done, and treatment should be done as needed.
When proper steps are taken and your health is maintained with proper consultation with your doctors, you can have a near normal married life ahead.
I hope this helps.