A good read here (Dec. 2017). It is illegal to send private money directly from the United States to Iran. Even routing thru a third country can put you in legal jeopardy. American banks can not deal directly with financial institutions and there are restrictions on what the money is for (humanitarian reasons) before an American Bank can even route money to Iran via another country. And loans or financial aid are definitely out of the question.
You failed to fully research the section of the Secretary of the Treasury restrictions and have noted exceptions to some trade exceptions (if they even still exist, after Trump decertified the Iran Nuke Deal and put back in place sanctions that were lifted by signing that deal).