once I begin thinking about a difficult decision my tendency is to want to keep going and reach some sort of conclusion

I think I remember reading that although making decisions causes decision fatigue, researching decisions does not. So you might try spending a lot of time brainstorming pros & cons for your decision, finding quotes from studies, etc. and compile them in to a big document called "guide to making decision X" for your personal use. The idea being to defer the actual stress of making the decision for the future and be able to do research, brainstorming, etc. without using up Stress Points.