Even if I sit here and think I WILL BE POSITIVE and I do the affirmations, etc, it is all fake because it is not even how I really feel.
This is your problem right here. From my own experience, it does absolutely no good to fake positive emotions - they have to be genuine.
A trick I learned from the Abraham-Hicks books, which really helped me: don't be so intent on being "positive". Sometimes the distance from here to there is too great for us - instead of trying to be "THERE", focus instead on making steps in the right direction. ANY step in the right direction is a good one, no matter how small, so be happy and grateful for them as they arise.
The other thing is, don't mistake "positive" with "socially acceptable". This is about you feeling good, not about feeling in a way that you think other people think you should feel. If it makes you feel a little bit better to vent your rage and frustration, then that's better than faking a happy smile and feeling terrible inside. The hope is that you wouldn't dwell in rage, but could then find an even happier / more positive perspective from that vantage point. They rank the various states of emotion, and the point is that if you're moving towards a more positive emotion, even if it's from "crappy" to "slightly less crappy", then you're headed in the right direction. Choose the thoughts that make you feel better, not worse. It sounds like trying to be "positive" is making you feel worse right now.
Does that make any sense?