There are many different types of SSRI (selective seratonin reuptake inhibitor) antidepressants on the market and often finding one at the correct dose that works for you is a matter of trial and error.
You won't feel much effect for a few weeks until your body builds up a sufficient level of the drug for it to have a consistent effect, so it's very early days yet.
It's worth trying alternative (non-drug) ways of boosting your mood, some people swear by strenuous exercise, others find some other creative outlet like art or music. Whatever suits you.
@Cyberus. I get grumpy and irritable if I don't exercise for a few days, an endorphine rush is a very addictive thing indeed! It's preferable though to my historic vices of tobacco and alchol (quit the former eight years ago, the latter is in moderation). Some people have addictive personalities and your example of hitting the "Moroccan mixed-herbs" shows how easy it is to get dependant on something that sheilds us from reality.