How do I keep damp moister out of my cellar?

You should be using a dehumidifier. Humidifiers put moisture back in the air.

You can also use Damp Rid. I would recommend using the large bucket version. You may need more than one.

Dehumidifiers are rated by square footage. Yours Is probably too small for the space. You might need either a larger dehumidifier or additional units to go with the one you already have.

You may have to paint any cement blocks with Dryloc to keep some of the moisture away. You may also have to run more than one dehumidifier--I run two from late spring to early fall and I have to empty them at least once per day. The heat in the basement in the winter keeps things dry. I see that you mentioned "cellar" rather than "basement". A cellar would be another story...if you have an old house with a cellar it might be much more difficult to keep it dry. There could be water leaking in from an old foundation.

We have a crawlspace , and we had a commercial grade dehumidifier put in that is connected to the water out take pipe , so we never have to empty it. There is a humidity setting on it , so it only runs when the humidity gets to a certain level. You really need to find the source of the moisture , you might need something like a french drain system outside along your house.