pregnancy ruined my hair

Is my hair problem a result from my last pregancy, being over 40 or a mix of both?  I am blaming the pregnancy but regardless, I am not sure what to do.  I want the hair of my past...soft, full, manageable.  Okay, maybe that description is the hair of my dreams but you get the idea.  Something happened during pregancy #2.  It turned dry almost brittle like and became frizzy.  I was taking prenatal vitamins, eating moderately healthy and washed my hair every 2-3 days but it never improved.  I started using expensive deep conditioners and went to my hairdresser more often for trims but this didn't help either.  I thought that once the baby was born all would return to normal.  Well, it has been four months and my hair is still "strange".  I am not sure who my hair thinks it is but it certainly doesnt belong on my head!  It is frizzy although not as dry, a cowlick has developed in front of my side swept bangs making them want to go the opposite direction and this "poof" is happening on the sides.  Now, I don't think I have a difficult hair cut- it falls just below my shoulders, is straight, has long layers with a side part and bangs that fall to the left.  I have had this cut for years with no real issues.  I dread washing my hair knowing that it will be difficult to style.  I still use the conditioning products, add a de-frizzing liquid prior to drying and add a styling pomade throughout the day to calm it down.  I am still not happy.  Oh, and to top it all off I have hit that postpartum time when all that extra hair you grew while "with child" starts to fall out.  Even my hairdresser is stumped.  Does anyone have a suggestion?  Have you suffered from this too?  Let me know.  I will post your comments on the blog.  Maybe together we can figure this out.