To me this song means you see a family member getting in trouble, and you try to give advice, but the person doesn't listen and continues getting into trouble...no matter how much you talk with him. Even when we have talked about and agreed that the things he's done have always gotten him in trouble.

After a while, I began to feel all the weight of his problems on my shoulders.

The part, "Misery Loves Company," I don't understand completely, but I don't think I would want company who loves misery. I don't like misery. I just wish he could have heard me and really taken my advice to heart, because the things he's done have caused me a lot of misery, and it does feel like a heavy weight on my shoulders.