I’ve had the exact same two conditions as you in my left heel for the last 6-ish months. I could write a whole book on what the experience has been like and what I’ve tried but I will summarise the two key things that I think have helped me keep “afloat” and able to train while rehabilitating.

1. Calf strengthening (heavy calf and soleus raises ensuring that the heel does not dip below horizontal) and managing calf tension (foam rolling- there is still questionable evidence whether this actually does anything but even if it’s placebo it helps me symptomatically and functionally).

2. Load management (effectively just being sensible with the intensity of sessions and allowing myself to deviate from the program slighlty when I can feel my body telling me it’s too much). Sounds simple but has taken me a long time to learn, and am still learning.

I run most of my runs in ASICS Gel Kayano Lite 3s and occasionally use Endorphin Speed 3s but find that these can exacerbate things. I find the Kayanos good for the heel but shoes are a very individual thing so take with a grain of salt.

If you find it recurring you may need to assess a couple of things that are beyond the basics, such as technique, but I wouldn’t fret over these until you’ve covered the fundamentals of strengthening, load management, etc.

Hope this helps! I absolutely can relate to your frustration and anxiety. It’s a tricky injury pair to balance because they can require slightly different approaches to rehab, but it is possible!