Do you mean you were granted asylum in 2000? If so, did you then obtain a green card based on asylee status? If you went back to your home country and lived there for several years after having claimed fear for your life and safety in that very country, obviously the government will have a problem with that. Furthermore, if you did obtain a green card, you probably abandoned it if you remained abroad for such a long time without keeping ties to the U.S. Contact an immigration attorney directly for more advice geared to your specific situation.
This advice does not form an attorney-client relationship and is merely informative. It should not by itself be relied upon to address a legal concern.
You will need to contact the U.SD. consulate int he country where you are living to apply for a travel letter. If you can get this then once back in the U.S. you should immediately apply for permanent residence. There may serious issues with your having traveled to your home country as your asylum status indicated you were afraid to do this.
If you were granted asylum and returned to live in your home country it is likely that the government may have some issues with the US government believing that you are truly afraid to go back there. There are a number of other issues that may arise with Asylum, including the fact that you are residing in a safe third country. To apply for Asylum you need to be in the US. If you are outside the US you can apply as a refugee to the UNHCR.