That's right, there are many other good ways to entertain yourself if you feel sad and feel like you're alone in life. Yes, it hurts to be left behind but it doesn't mean the end of the world for you, you have to get up and move on because there are many other opportunities waiting for you. Don't ruin your life with gambling, there are many other things you can do besides that.
I think loneliness is the reason why people want to gamble, it's too kill our free time. But when you feel sad and feel alone in this life, that means you're not in a good condition, so could do something stupid or may harm yourself. To overcome this, one should try to deal with himself, try to find a good way to fill your energy. For an introvert can try to take me time, while for extrovert can try to meet with other people.