My finger is infected. treatment?

Finger infection: This can be somewhat serious depending on the degree of infection. Not to scare you, but think of what could happen if the infection got out of control. That's why you need to supply more information about a) how it happened, b) what extent is involved, c) if there are associated symptoms etc. The 'hand' and fingers are too important to deal with 'lightly' in an online forum such as this. See MD.