I noticed you cite an "extremely stress-full period of time" you endured. This sounds to me that your nervous system has been compromised. I myself suffered a nervous breakdown due to extreme stress at work, however leading up to that period in my life I suffered longtime with horrific IBS type symptoms and general toxicity. The tingling/biting under the skin sensation is your nervous system. I suffered this, it was so bad at one stage that I would be awaken around 3am in the morning with a sensation of something in my blood crawling from my feet and working up to the top of my head, including in the balls of my eyes. It was pretty horrific. A Dr in Kinesiology resolved that particular issue with various supplements. However, the bigger picture is that you are experiencing some kind of bigger health imbalance. Unfortunately I won't even attempt to suggest what is the root cause. Diet, lifestyle and emotional issues need to be addressed. A visit to a functional medicine practitioner, doctor in kinesiology or undergoing Biofeedback testing would be worth pursuing.