Never ever will I use Sertraline again. It made me so sick that, landed in hospital. It was the worst 6 weeks in my life. They suspect that i am alergic to sertraline. The side effects were so bad,I thought that I am loosing my mind. I felt so aggresive towards myself.
Yes, I've been on divided doses for years and years because of the sedation caused by antidepressants. It's a common thing to minimize side effects.
Awaking after 3-4 hours, is typically an anxiety issue (your body's received enough physical sleep, and while your brain would like more it's too stirred up). Calming routines and quiet breaks during the day may help. Avoid caffeine, try to eat 'clean' healthy foods.