Mother Theresa gave Freely!

   How much is to much?   How much time and energy do you put into a giving of yourself?.  Do you run yourself ragged and give your family the leftovers?  What lines do you draw to make sure your life is balanced?  I find that I have no problem saying no and meaning it.  But sometimes I get myself in situations where I want to do for someone and then they take advantage(in my opinion).   Then I'm upset because they took advantage-But did they "take" advantage or did I give it away.  My self inflicted Catholic guilt kicks in and I feel guilty for being upset at the person and when I offer to help it should not come with strings attached.  I'm a dog chasing my tail.  How do I let go of the hurt of being taken advantage of and just give freely?  I'm not certain that there is a pat answer to such a complex feeling.
    I imagine Mother Theresa never felt frustrated giving 100% to the orphans and nuns.  Is this because she didn't have children and a husband she was taking time from?  This might be another reason I feel guilty...I give to others at whose expense?  Do I give 100% to my family?  Or do I, on a regular basis, give away my best self to others?
    In reading what I am writing I see the decisions I make directly effect my domino's(those who I directly impact and bring down with me when I fall).  How can I change my actions so I don't negatively impact those around me?  More importantly, what can I do or change in myself that when I do give my time and energy it's a positive impact on those around me?  I think I have a list to guide me and possibly change how I view the giving of myself.

1. does it take away from my domino's? 
2. Can my domino's be involved and make a difference?
3. do i love what I am doing, does it make a difference, it is important?  
4. can I fit it into my schedule without causing stress or conflict?
5. Am I the best version of myself when doing this?