I had a similar problem. I now maintain a simple TODO note on my phone and organize the items by priority sections (Now, Soon, and Eventually). I check off the items once I’m done and remove them after a while. This does a few things:

  - Relieves the stress of having to remember random stuff that comes up during the day
  - Allows me prioritize my worries… the “Eventually” category usually consists of lower-priority things that would have low impact if I didn’t get them done soon (or at all in some cases)
  - Gives me a sense of accomplishment when I check off an item

I like this better than the iOS Reminders app since I have more control over various things (with a huge disadvantage of it not being time/date-aware.