Stop being envious and start to be grateful for the things you have. Which is a high order, but if you just keep desperately wanting things or wishing your situation is going to get better, its not. Wanting doesn't do anything. It only makes you feel worse.

[Which is something that he needs to follow himself, but...at least he knows the hell that it is.]

You are not Misa. Your situation and hers may look similar, but they're different. What happened, happened. You can't go back and change the past.