I'm not sure where my idea of karma came from. I suppose a combination of beliefs I've studied mixed with my personal perspective... Karma, for me, is doing decent things for others & yourself so you have some leftover to be selfish with!! Hahaha. Everyone deserves indulgence. If you work hard, if you're useful & productive, there is no reason why you shouldn't be able to play around with your karmic buildup.
My next life, if there actually is one, doesn't feel like it should be dictated by karma. If anything, it should be dictated by self-awareness. Because ultimately, you create your own reality with every thought & every action you create. Even in disliking your place in life, you are still perpetuating it. If you have self-awareness, though, you are at least being proactive...
Hoping some higher power is going to do the hard work for you is silly, in my opinion. You're not taking any initiative in the course of your own life, whether you think it's pre-written or not. You might as well make active choices & decisions, thinking they have already been made, than being boring & complascent.