Here's a twist on positive thinking: don't just practice finding the good in people; notice their blind spots, too. Where are they having an impact that is different from what they probably want? What might be helpful for them to learn that they don't yet know how to do?
Sometimes, it doesn't seem possible or even right to be "OK" when someone we love is suffering or struggling. And often, that means we end up giving and giving and giving. Sometimes the best thing we can do for everyone is to give to ourselves first.