How long it takes depends a lot on the group of elders you are dealing with, the ones that Dfd you. A friend of mine went back after being Dfd for fornication and it took them a year of non-stop meetings and groveling at the back of the hall.
If you intend to fade again or become pretty much inactive, it will be up to your family how closely they associate with you. You know them better than us. If you think you can pull it all off, it might be a way back to your family. A hard one, though, to say the least. Best wishes to you.