To be honest, it might be difficult. People often assume that we have complete control over our actions, feelings, and personalities, but we don't. Changing deeply-rooted parts of your personality like that takes time. Its not something you can just wish to happen and have happen. I guess in this case I could just say to try and "live in the moment" more [that's essentially the mindset I live in, and it works fine for me], or find some other mindset that works for you, as in, one you feel comfortable in.
In the end though, at least from my experience, there are only two ways to change things like this with any degree of speed. First, you would have to go through some sort of hardship or traumatic experience, as often, it takes real suffering and pain to shake people out of their habits. They often say that true wisdom is earned. Obviously though, that's not something you can control, or something you would really want to happen. The second, and more viable way, is to simply contemplate these things deeply for long periods, running through it in your mind, breaking it down and such. By doing that, you can attain wisdom on it that you wouldn't be able to get through a normal level of thinking. Doing that takes dedication however, for you to truly want whatever it is you're thinking about to change, for you to keep thinking about it continuously [obviously you wouldn't think about it constantly, but it would be there in the back of your mind and would be one of the things you'd be thinking about regularly], and for you to exert yourself mentally, exercising your full mental acuity to figure the problem out.
Remember, wisdom is different from intellectual knowledge like the trivia facts we aspies are known for. Wisdom, although it can be told to you time and time again, is a kind of knowledge far deeper than simple factoids like we usually think about. Wisdom is something that has to be absorbed at a deeper level and truly understood instead of just being recorded as a simple statement that can be played back as needed. In essence, while other people can help you with this, giving you advice, which would certainly be helpful if you felt comfortable talking to them about it, but in the end, its something you'll have to do yourself. I say this from experience, as I recently had something about myself that I felt I had to engage in that very process to get through, and it was actually only by a combination of both the methods I named to you that I was finally able to get over it.