How fast can I make my depression go away?

Not FAST. With appropriate treatment (usually psychotherapy + medication) the depression will gradually lighten over a 2 month period. You will still have better and worse days but, in general, each moth will be better.
5 years. It takes several weeks to 1 month to see good effects of most antidepressants (ssris) but usually drs do not stop them until they are reallyy doing well for some time around 5 years. Depression has a tendency to come back ofteh otherwise.