Ask your doctor if you can take half in the morning and the other half in the evening. That might work well for you. I know I've done this with a few different meds, after asking doc, and it was fine. Blessings - Blu
I agree with blu about asking your doctor about trying divided doses and see if that helps with the afternoon slump.
If not, discuss the SHORT TERM use of a low dose benzo until the Zoloft kicks in fully.
Peace
Greenlydia