Eating a diet low in red meat and drinking a lot of water can improve your numbers. Dehydration can really mess with your numbers.
That would be a question for your doctor. Everyone is different. For the creatinine to be slightly elevated like that, I wouldn't be concerned at this point. It can change depending on how much protein you consume, if you don't have kidney disease. If there was anything to be concerned about, I'm sure your doctor would have told you. Don't let fear consume you. Stress only makes things worse.