Depression/Bi-Polar & Zoloft

I heard not long agon that a person taking Zoloft committed suicide.
When I went without my 300 mg a day Zoloft for 48 hours I indeed felt
very horrible, but not ever while on it. I am wondering if this person
might have done the same as I, and decided to give up on living due
to the imbalance created by the drug being depleted abruptly in their
system.

The doctor never gave me a psychiatric evaluation, but merely put me
on the drug because I said that I could be crying one moment & laughing
the next and wondered why. He didn't even check to see if I needed a
hormone adjustment, and I did tell him I had a full hysterectomy in 1991
at the age of 24 due to cancer.

I have never been told I was depressed or bi-polar until this doctor,
and I HAVE asked other doctors if I might be and they said what I
said I was feeling sounded normal to them, like mood swings bascially
fomr a hormonal imbalance. This drug costs me $280.80 per month,
and I can't afford paying that for something I might not even really need.

Why are doctors so eager to place us on these drugs and label us
depressed or bi-polar without any real investigation into the matter?

Can anyone please help me understand & give info. & suggestions?