Is it legal for workers compensation to stop my benefits without notifying me first?

In general, a Plain Language Notification is required whenever an adjuster changes your income benefits, either by increasing them or decreasing them, converting them to IIBs, or whatever the case may be. The PLN is something that issued at the same time the change in benefits occur, so it could take a couple of days for you to get the notice in the mail. In your situation, no longer having an attorney is not a legitimate reason under the law for stopping benefits. Some investigation needs to be done to learn why the insurance company stopped benefits, and why you did not receive an accompanying PLN. You could either trying calling the adjuster, or their supervisor, contact the Division of Workers' Compensation local field office or contact an attorney to do the investigating for you. Whether or not it is likely for the benefits to start back up again depends on the reason the benefits stopped.

I agree with Sean's answer that when an insurer stops paying benefits (or changes the amount of its payment), it should file a PLN (plain language notice) advising you of the basis for it. It is possible the PLN just did not go out, got lost in the mail or went to the wrong address if you have moved recently. I doubt the insurance company stopped paying just because you no longer have an attorney. I would call your adjuster and ask about the change in your benefits. If you don't get through to the adjuster, call the local Division of Workers' Compensation field office where you claim is assigned and they should be able to look that up for you without too much problem. If you don't get a satisfactory response, you may want to consider speaking with a new attorney.