Can my finance fix my papers? He is 17 and I just turned 18.

It may be possible. Your fiancé will need to be at least 18 years of age to file in order to sign an affidavit of support. The forms required and costs involved will greatly depend upon your immigration history. For example, if you previously entered with a visa and your fiancé is a United States citizen, you will likely be able to seek adjustment of status. This is a less complicated process. You should consult an attorney to discuss your immigration history. In the interim, you can read more about family immigration at http://myattorneyusa.com/family-immigration.