Hi LonelyTree, and sorry to hear. I fully believe you've been happier in years after taking fluoxetine, but 20 mg is a small amount and two weeks is a small period of time, I would question whether it's really having such a big effect on your mood so suddenly - is this your first antidepressant? Give it some more time I'd say, but if you think things are better, then having had drinks on one occasion isn't going to jeopardise the fluoxetine treatment. Alcohol will make you drowsy more easily and basically the effects of it will hit you faster. Small amounts of alcohol can cause euphoria, but the aftereffect results in a certain reduction in mood and does cause anxiety which may be what leads to the crushing sadness. As soon as the alcohol is out of your system (fairly quickly, unless you're intolerant to it), the meds won't need to kick in again like they did to begin with. Just continue as normal and note the effects over a longer period of time.

And yes, I totally know about the yawning - I get that a lot too as a side-effect (I'm not taking fluoxetine), but I'm not sure what causes it!