Part of the problem is that you are trying to, essentally, think away your thinking issue....this cannot work.
As hewhomustnotbenamed said, it is better to allow thoughts to arise in your mind, as that is the natural process of mind, but try not to cling to them; that is, try to let them flow through your head without actually attempting to impose structure or meaning onto them. This is best done thrugh practising meditation, where the aim is not to stop thinking, but to FOCUS the thinking on one specific thing- eg. your breath. The more you practive ignoring distracting thoughts or at least, not pursuing them, the more you can hone your attention so you can think about what you need to.
Bear in mind this- humans are animals that can think. That is our curse and blessing. We have thought out meanings for the contents of our galaxy, thought up gods and demons, thought up world wars, thought up beautiful poetry and art, etc. To stop thinking, for a human animal, is either a result of massive mental retardation/damage, or death. To control thinking/thought and to channel it properly is to be human and happy.
Thoughts are like currents in the ocean, all zipzapping around and entiwining with each other...its hard to pick out one precise flow to go with, but with concentration and THOUGHT, one can begin to discern the differring patterns and thus choose which eddy to follow.