R.W.
Ok, this is going to sound perhaps a bit strange but...I had this same problem with my little girl from newborn to about age 2 1/2. Do you know what made a difference for me? Just being much more "into" being a Mom. I wasn't really ready to be a Mom and felt tired, confused and generally overworked. I was a single Mom, who had a strained rela with her Dad and missed being able to do what I wanted when I wanted. Finally, after a lot of soul searching, I realized that my daughter really needed my true love for her. I released my resentment, embraced my love of and for her and for myself as a Mother AND a woman. THen, she began to sleep well.
Medically, I stopped giving her sugar ( the white, bleaced, bad for you table sugar), started giving her natural herbs from an accupuncturist, started her and I both on an organic/local diet and things really changed. This all happened over about a 2 year period. Now, she is 6 and is a terrific sleeper. Wow.
I hope this was helpful. I just wanted you to know that you are not alone, there are many things you can do and to be loving to yourself. You are a strong woman and this is a learning experience.