Hi and welcome to the Chiari forum.
Many of ur symptoms sound like chiari symptoms and if u r getting new symptoms then yes it is getting worse...it is changing ur quality of life.
Going back to a NS that did not give u more info may not be a help...u need to see a true chiari specialist and be sure that u do not have other related issues going on as well.
The mass u mention is it a syrinx?....a cyst that fills with CSF fluid?
Here is the link to a list of drs u should research and keep in mind u may have to travel as we r all not lucky enuff to have a chiari dr in our area.
U deff need to be seen by a chiari dr...do u have copies of ur MRI and the report...if not request them and going forward always ask for copies of all testing even blood work.
"selma"
http://www.medhelp.org/posts/Chiari-Malformation/LIST-OF-CHIARI-SPECIALISTS/show/1293483