I think so much of love is habit...my husband is working hard at getting in the habit of doing loving things for me...saying I love you every night...kissing goodnight...being thoughtful...doing for others.  I believe you can develop good habits over time just as you can develop bad habits.  And yes, it is a choice...you can wallow in misery & find fault in everything or you can look for the good & make the choice to love, nurture & cherish someone.