Pondering relationships...

So, I've been pondering the concept of relationships for quite some time now - more so these last few months after moving away from the place I've called home for 27 years of my life. Distance truly shows a relationship for what it is. Those who want to have relationship with you will keep in contact and I with them. Others fall by the way-side. One only has so much time, energy and resources to invest into relationships, thus limiting how many relationships one has. Of course they range from acquaintances to kindred souls.
Today I read a quote that I am applying even more so to my pondering - "You can NEVER please EVERYONE but you CAN please God."
Here's some background - There are some in my life with whom I am expected to have relationship, some familial and some in other areas, however I have found myself frustrated when I try to invest in those so-called "relationships" and there is no reciprocation. What I refer to in "investing" ranges from texts, Facebook messages or e-mails, phone calls, giving gifts for birthdays or Christmas, invitations to events, etc.
When I do these things and receive no response or reciprocation I wonder, why do I even bother? If so-and-so doesn't want to invest in a relationship with me, then why do I even try?
This question comes up more so with those that I am "expected" or "obligated" to have relationship with. To take that a step further, I have found myself wondering why on earth anyone would want to be in a relationship by "obligation" and is that truly even worthy of considering a relationship?
Of course there are people in one's life, an extended family member or so, who you may occasionally come into contact with and, out of family obligation, are polite and endure a conversation; however that is not the relationship to which I am referring.
As we start our new little family with the expected birth of our first child in just a few short months, I've begun to analyze my relationships and who will or will not be in relationship with us and our child. In our own family the relationships vary so greatly. My husband's father and brother, who both live in Texas, his mother, who lives in Illinois, my mother, who lives in Oregon, as does one of my brothers, and then the remainder of my immediate family live 5 driving hours away. Two of my cousins were like brothers to me growing up and we have stayed close, while the cousins on the other side of my family I hardly know and have exchanged less than 50 words with in the last 5 years combined. Parents, step-parents, grandparents, aunts, uncles, cousins, step-cousins, step-siblings - there are so many people who are in our lives, all with varying degrees of closeness.
Honestly my heart wants to spend time, energy, and money on and with those with whom I am close and have a valuable relationship.
So, since I can NEVER please EVERYONE, including those who expect me to have relationships with those that I'm "supposed to", what is my responsibility and how do I please God ALONE in my relationships?