Panic Attacks duting Pregnancy

This is my 3rd pregnancy. My first was difficult because I was going through a divorce. I had panic attacks often and had a lot of self esteem issues. My second pregnancy was picture perfect. My husband and I are wonderfully in love and we weren’t having any issues. This pregnancy, which is my last, I’m having some strange feelings. I can’t rub or touch my growing belly without feeling like I’m on the verge of a panic attack. I also keep, without touching my belly, getting feelings of being completely overwhelmed and like I’m about to lose it. Before I really started having these feelings, I went to my doctor about being depressed. She put me on Zoloft and I’m only taking half a pill, once a day. I’ve been doing that for about 2 months now. Does anyone have any advice or tips? This is becoming overwhelming for me.

I guess I should also add that I’m nearly in my third trimester. We’re due at the end of April.