Six years I divorced and according to my divorce agreement for spousal support there is not an ending date. Can I appeal this?

In order to answer this, your final decree must be reviewed.  The appeal time has long since passed, but that does not mean there is no recourse.  I would not feel comfortable saying you can or cannot change this, without looking at your divorce papers.  We would gladly review it for free, if you would like us to.  There are other lawyers who would probably be willing to do the same.  But make sure someone reviews it and tells you your rights and obligations.