Working too much is not an acceptable reason for missing your requirement to report. Sometimes you may have to miss work so you can report.
So far you are risking having at least your probation revoked which could very well result in a parole violation. Unless you enjoy time in prison do anything it takes to resolve this situation would be a good idea.
Yes you should be worried, very worried.
What I would be worried about the most right now is it may already be too late to keep this from sending you back to jail or prison.
There is quite likely a warrant for your arrest already. If you want to wait until you get picked up it is surely going to put you at a disadvantage. Being proactive always gives you more control over the situation than being reactive.

