Whoever the person was who diagnosed you, should have referred you to a nephrologist (kidney specialist). The nephrologist, in turn, will no doubt refer you to a ''kidney nutritionist''. You are going to need one of them ASAP. I don't want to scare you, but no doubt you'll need to be on a kidney diet, according to your GFR result. This is no easy diet. On the contrary, it's hard. But it IS DOABLE! It basically involves cutting out (as much as possible), potassium, phosphorous, sodium, protein. You will be given literature explaining all this in more detail, I'm sure. Are you also diabetic? You will also have to keep your blood pressure under very good control.
Hope this helps. Get to the neph pronto!