I can relate to this a lot. I try to follow everyone's advice to stay positive, but there's that little voice telling me otherwise in my head. You sum it up perfect: it's like, "Nice try."

My therapist has done some mindfulness stuff with me that teaches you to accept and validate your response to a situation, for instance, by saying to yourself, "Things are hard right now and might be for a while, but it's not always going to stay this way," rather than judging yourself on how you should or shouldn't feel. I have a way to go when it comes to practicing this, but I like the concept behind it.