If you're sensitive to meds, benzodiazepines won't be the answer. I tend to be sensitive too, and I find that taking no more than half the suggested or prescribed dose is what helps. If it's a medication like and anti-depressant, that in itself could be causing your reactivity, in a sort of waterfall or domino effect. ANything that messes with your brain and central nervous system can produce a wide variety of unexpected, and unwanted, side effects.
Benzodiazpines will be, at best, a brief bandage over your symptoms, and after that, a severe potential worsening of them.
It's hard to know what to suggest, based on my own experience with being highly reactive to everything from foods to vitamins to herbs, without knowing a little more about your symptoms and issues.
Generally, what helped me was magnesium glycinate, among other things (potassium gluconate, Vit C, small amounts of melatonin), and a very specific way of taking it that worked for me when nothing else did, including large doses of the magnesium, which did nothing.
Also, remember the PR mantra .... whatever you try, start low and go slow, and remember that what works for one or two or five of us may not work for you. So trial suggestions very carefully.