It's literally like flipping a switch. One day, the plumbing works. The next day, it doesn't. Many times I'd just give up, out of boredom.
The side-effects are clearly stated but to use myself as an example, I vastly underestimated just how strong they would be.
That said, if you're dealing with the big black dog as it were, don't use it as a reason to avoid anti-depressants if you really need them. Keep your doctor up to date about the side-effects so they can adjust your prescription. And don't be shy just because you're talking about your private parts.
And make sure you have a therapist too.