Hi - I know it's difficult to do, but please try to stop worrying about whether or not you have kidney disease. I hope your kidney scan is done soon that you will know just what is going on!
As you said, whatever it is is in it's early stage. Remember, a person can function really well with only one kidney if need be; and I believe you said your problem is with the right kidney? The fact that you tried to overdose could have done some damage, but so far it seems as if you have an [I]infection[I], which may be or not be actual kidney disease.
I have recently learned that I have stenosis in my renal arteries. I had a kidney ultrasound, and the results showed some early kidney disease in both kidneys because of renal artery stenosis. However, my urine and blood tests were normal. I am a former smoker (20 years ago), and also my father had atherosclerosis. I have been told that I, too, have it and that is causing the stenosis. Is your blood pressure under control? Both smoking and hypertension can cause kidney disease. But, as others have said, kidney disease can be treated; and the kidney ultrasound is a good way to start. Good luck!