Hello~I am so sorry you are going through this, it is not fun. I am wondering if you changed laundry detergents, and they are not rinsing out well. Also, have you been tested for diabetes, sometimes in the morning, you will have itching if the blood sugar is a bit high, it isn't common, but can happen.
My first thought was dry skin, but you say you are using a moisturizer, so, that probably isn't the case, that being said, however, try taking a bath in Aveeno, this is an oatmeal-based bath that helps to sooth irritated or dry skin.
As to what type of doctor to see, I would see a dermatologist and if he/she can't help, then an allergist. As to creams, try using the highest over the counter cortisone cream you can find, this sometimes helps with the itching as well.
I hope you get relief soon.
Does it happen when you sleep elsewhere? Have you changed laundry soaps? Are you pregnant and taking an anti- morning sickness medication?
Here's from the Mayo Clinic's quite excellent post on itchy skin.
"Causes of itchy skin include:
"Skin conditions. Many skin conditions itch, including dry skin (xerosis), eczema (dermatitis), psoriasis, scabies, burns, scars, insect bites and hives.
"Internal diseases. Itchy skin can be a symptom of an underlying illness. These include liver disease, kidney failure, iron deficiency anemia, thyroid problems and certain cancers, including multiple myeloma and lymphoma.
"Nerve disorders. Conditions that affect the nervous system — such as multiple sclerosis, diabetes, pinched nerves and shingles (herpes zoster) — can cause itching.
"Psychiatric diseases. Examples of psychiatric diseases that can cause itchy skin are anxiety, obsessive-compulsive disorder and depression.
"Irritation and allergic reactions. Wool, chemicals, soaps and other substances can irritate the skin and cause itching. Sometimes the substance, such as poison ivy, parasites or cosmetics, causes an allergic reaction. Also, reactions to certain drugs, such as narcotic pain medications (opioids) can cause itchy skin.
"Pregnancy. During pregnancy, some women experience itchy skin."
That includes a lot of things that don't sound like what you're dealing with (for example, it doesn't sound like OCD or anxiety). But it's a way to start crossing possible causes off the list.