I'm always so slow and drowsy. am i just depressed?

No: You might have a thyroid problem. Hypothryoidism can make you feel "slow and drowsy" there are other medical conditions that can make you feel that way too. Find a doctor who will take the time to find the real cause of your problem and not just prescribe drugs for symptoms.

Evaluate: You describe low energy and difficulty with thinking. There are a number of causes for symptoms like these. Have your primary care doc rule out medical conditions using your history and risk profile. Major depression is a combination of symptoms - see below. If it fits, ask for a psychiatrist. http://www.ncbi.nlm.nih.gov/pubmedhealth/pmh0001941.