Help with dilemma!

I have a dilemma...

I purchased tickets a few months ago to go to Berlin from SFO (SFO-LAX-EWR-TXL) on May 22.

I just found out that I have to be in NYC on May 21 - May 22 AM, so work is paying for flight to NYC on May 21. Is there anything I can do to get UA NOT to cancel my entire SFO-TXL leg if I can make it to the EWR-TXL leg on time?

Any advice is much appreciated!! Thanks!!