I've only been on 150mg for 2.5 weeks and it makes me terribly tired during the day and especially tired in the evening, and having trouble sleeping at night even with AmbienCR. I have not noticed any improvement yet, but it appears that it can take 4-8 weeks to really start working. To switch and take it in the evening, since I've already taken it this morning, should I take another this evening or wait and take tomorrow's dosage tomorrow evening?