You'll really find it really hard to completely watch a drama if you are thinking of another drama while watching that drama. Try to immerse yourself in the new drama, don't think of Emergency Couple because by doing so, you'll only compare the 2 dramas then you'll lose interest because for you, EC is a better drama. Try your best to keep your thoughts off of EC. If you can't, then you can only wait until you forget(a bit) EC or find a better, in your opinion, drama which will be hard because your first love is EC and first love tends to be the sweetest and perfect and most lovely thing in the world. Just a tip, watching movies can help you find other dramas of your liking~
There are already very good suggestions, even dramas very similar to EC, in your past threads:
http://mydramalist.com/forum/showthread.php?6307-Recommend-Romance-drama
http://mydramalist.com/forum/showthread.php?6278-Drama-similar-to-quot-emergency-couple-quot
http://mydramalist.com/forum/showthread.php?6271-Drama-similar-to-quot-emergency-couple-quot