I was taking 37.5 effexor tablet and took it for 6 weeks but did not help. Dr. changed to effexor 75mg. Since starting 6 days ago am not sleeping as well and still anxious. Will I have to wait another 4-6 weeks for it to work again. So aggravated with antidepressants but can't stand anxiety so have to try something. Please anyone that could help with info. Also after I get used to it maybe will the insomnia go away.