The Question With No Answer

I'd like to be able to write that everything at my home has become wonderful ever sense we adopted our foster daughter.  However, I am a realist and I want to keep my posts as honest as I dare.  I love my adopted daughter.  I never question that.  I could never have made any other decision a year ago other than to adopt her.  I can't imagine her being in any other home.  I have seen first hand what some foster homes can be like when the well being of the child is not put first when making the decision whether or not to adopt.  So, I am glad that our adopted daughter is safe.  However, I also have learned that life can become very hard and stressful when any child is taken into a home who is not the family's biological child.  Sometimes it can turn out great.  In our case, and in the case of many foster and adoptive families, the child coming into the family can be so different in character, genetics, and personal background experiences, that there is just not much in common between parents and child.  We can make the decision to love and nurture the child, but extreme differences can cause huge problems in the way of communication, behavior, and even in interaction with the parent's own biological family, and in the marriage of the parents.
These are issues which we are struggling with in our family.
At this point, I have chosen to simply pick myself up after one of our many "head to heads" and do my best to move on.  The probem is, the issues come up daily and I find myself losing my patience more quickly and it does, at times, become more difficult to pick myself up and continue on.  For those of you who are searching sites such as this one to find answers on how to cope with this problem, I am afraid I do not have any.  I am in need of advice myself.  How can I love my adopted daughter and yet feel so resentful towards her for the stress that has come into my home.  And THAT is the question that does not seem to have an answer.
To anybody reading this who does have some advice about this, particularly if you have experienced this yourself, I would love to hear from you.