how does zoloft-induced insomnia feel?

I am thinking about starting Zoloft, but I am worried about side effects. In particular, I already have problems with anxiety-induced insomnia, and I am worried Zoloft could make it worse. So, I am wondering - how does Zoloft-induced anxiety feel? Are you awake throughout the night or awake and still anxious? If it just keeps you awake and removes anxiety, that would still count as progress :) Let me know about your experience with this!