I've been taking premarin (conjugated estrogens) .625mg for 30 years, since total hysterectomy. i am now 59 yrs old. would my body go bonkers without taking it?

Possibly: It is difficult to say how your body would handle discontinuing your hormone replacement. You should at least be tapering down to the lowest effective dose. I would talk to your provider about decreasing or lowering your dose.

No but: You are on a low dose of estrogen and your body would not "go bonkers" but you may begin to have hot flushes, vaginal dryness, insomnia, and mood swings. Without the estrogen your risk will begin to increase for stroke, heart attack, colon cancer, alzheimer's disease, and osteoporosis. It is not unsafe to continue your premarin (conjugated estrogens).