Extreme itching

I am terribly itchy all over my entire body. There is not a rash or hives really either. Just red marks where I have been scratching. I am about to crawl out of my skin!! I am 32 + 3 with twin girls. I am huge but it's not only my belly that is itchy. I have been taking benedryl all day long as soon as the time expires to be able to take more. I have taken a shower, taken a batch with baking soda. I've used an entire tube of hydrocortisone cream, lotions, and went and bought Sarna anti itch lotion... I don't really want to make a trip to the ER over itching but I jushave don't know if I should chalk this up to another joy of pregnancy or if it's something I should be concerned about. Any advice would be appreciated since I am a FTM! TIA