Hi mags, I started on anti depressant since being peri menopausal, mines a trycyclic one of the side effects is sleepiness, I take mine about an hour before bed, at first improvement was slow and very up and down. I been on them around 2 years and for the vast majority of the time they have been a god send. At the moment I feel they are losing their effectiveness, so I'm keeping an eye on things in case a change is needed.
If I can remember correctly I think improvements were subtle, but as time goes on you will find you improve on a month to month basis. That's how it was for me, hope this helps . Anxiety is horrible, and quite hard to explain to people who haven't had it. x