Olanzapine howling before it works

i was prescribed Olanzapine to compliment venlefaxine for my depression and anxiety and had two improved weeks but today not so good, just wonderi go whether im getting full benefits as yet as understand could take a few weeks to get full effect? Only on tiny dose 2.5 mg at night whereas my Venlefaxine is big dose 300mg pd. 

Advise would be appreciated.

Ps it's how long not howling! Lol 

Aspinal howling ?dont get it 

Hi Eli, should have read "how long" Lol N 

oh i see hahahah!!