I Have Had 3 Consecutive CBC's Over The Past 4

I have had 3 consecutive CBC's over the past 4 months. My platelet count was low and each consecutive platelet count was lower. Last was 96,000.
I take 3 Benadryl capsules each night for allergies and stuffy nose It also helps me sleep. I'm checking side effects of all the drugs, vitamins and supplements I take including Benadryl.