2 books I think should be brought to some people's attention.  The Complex PTSD workbook by Arielle Swartz and  Healing the Trauma of Domestic Violence by Edward Cubany.  I know I personally have these issues.  While I may have healed I am still not done healing.  The reason I do allow myself to be treated as less than I deserve is because I do not expect to be treated well by the average person.  We allow what we expect.  I'm slowly setting my standards higher in my expectations of how others treat me.  These books will hopefully help me heal even more.