I’ve had a Morton’s neuroma for several years. Typically these are caused or aggravated by tight shoes. Mine came on after my doctor put me on statins and the nerves in my feet went haywire. (It’s a rare-ish side effect.)
I agree that stretching helps a lot. You can get devices that separate your toes, taking pressure off the nerve with the neuroma. I also have a round pillow that slips over my foot or ankle. Wearing this donut keeps my feet from squishing (a medical term) each other when I sleep.
Finally, I was told by doctors and the old guys at Public Shoe in Clarendon to get wider shoes. Luckily Shimano now makes mountain bike shoes with plenty of room. A better, albeit more expensive, choice would be shoes made by Sidi which seem extremely popular around #bikedc