An answer to: how do I still my mind?

Are you able to be objective to your thoughts? I mean, if you constantly have thoughts about a problem I think to be mindful about the fact that you want to solve the problem by understanding it deeply enough to actually do that (solve it) is the way to go instead of just beeing bothered about an endless stream of thoughts about it that don't solve anything because they are too shallow and negative. If you are aware of the fact that you have a problem and want to solve it you may get assistance; a brilliant thought comes in and interfere with the bunch of stupid and negative ones and are able to dissolve them because the interfering thought is more vibrant and true and was the thought missing to be able to understand the issue and be free from it. Then it is easy to decide not to think about anything and focus on something else than thoughts, or continue to be objective to thoughts and detect new problems to solve the same way. The purpose of meditation is not to supress thoughts, as you know. You don't get rid of thoughts that comes because you need something enligtened. Meditation makes it possible to understand things deeply and become less disturbed as the problems are being solved. Some call this deep state of being when you understand fully contemplation. There is of course thoughts that are just loosely connected to a problem and that are not worth spending your attention on. Then you can, not suppress, but push them away as if they were flies in your face once you are aware of their insignificance. You are in control of what you want to focus on.