I am so sorry that you are in the situation you describe.

When I was on Sertraline, my prescribing physician said it might be four to six weeks before my depression and anxiety lessened although he believed some things, like sleep and appetite would improve before that.

Of course, this medical advice was given to me personally by a doctor familiar with my complete medical history and so on. And it has been more than 20 years since I was on Sertraline so I don't know if even general advice about that med has changed since then.

While on this med, I had these two side effects: daytime sleepiness and nighttime insomnia. And I didn't think the Sertraline ever produced optimum resolution of my anxiety.

But I am not a doctor or medical professional so I cannot offer any kind of information that you could or should rely upon!

You mentioned something about being able to take only half of the Sertraline that was prescribed for you. Does that mean that your physician has reduced the dosage by 1/2 or that you yourself are taking half of the what your prescribing physician prescribed for you?

I have read that taking medications at lower than prescribed doses can sometimes produce unwelcome side effects without the intended therapeutic benefits. So I suppose that is why one has to work closely with one's doctor and follow medical advice or else seek a second or third medical opinion if one has doubts about that advice.

As a mere layman, I would worry that if you are taking half of what was prescribed to you that it would be helpful to you if your physician knew this and about the troubling side effects you are experiencing.

Sometimes an augmenting medication can be added or a med switch can be helpful.

It is awful that you are having lightheadedness and dizziness. I once had horrible side effects from an early tricyclic antidepressant. Sertraline saved me from these and was quite an improvement.

I sincerely hope you can find something that helps you and gives you optimum relief with the minimum of side effects or at the very least, the minimum of unwelcome side effects.

I fear that my response has been worse than useless to you and hope that others here will see your post and craft a response which proves truly helpful to you. I am so sorry that you are suffering!