With any form of dis-harmony or dis-ease, you'll go through peaks and troughs with it.
Sometimes you'll feel too lousy to even think while other times you'll feel considerably better.
The time to do vibrational work is in those times when you are feeling considerably better.
During the troughs, just let them pass in their own way. Doing vibrational work in those times will just annoy you and probably make you feel even worse because it will remind you how much better you should be feeling - and you'll just get mad at yourself for letting things get so bad.
During each peak, however, you have the chance to improve your condition with some focusing.
It's like pushing a child on a swing. Each time the swing comes back, you can use the existing momentum of it to push it and make it go higher and higher.
But the time to do this pushing is when the swing is already going in the right direction (away from you). If you try to push it when it is heading towards you, you'll have a hard time.
As Shakespeare said...
There is a tide in the affairs of men.
Which, taken at the flood, leads on to fortune;
Julius Caesar Act 4, scene 3, 218–224