Definitely sounds like a progressive problem. I would keep getting on to your hosts support as things are only going to get worse.
Once your memory runs out you will be watching all your
website hostings and your server slowly collapse and crash. Then you won't even be able to view the
website hostings let alone use cPanel.
Your host must be treating this is a high priority techinical support problem - in my opinion it sounds like one that needs immidiate investigation and an efficient solution.