My big toe has been numb for a few days after wearing heels. I don't have diabetes or back pain. What can I do before going to the doctor?

Let it relax for. A while and wear open sheos to relieve the pressure on it and take some Motrin and warm soaks for the foot.
Avoid the heels. Limit use of the heels to see if you notice any improvement. Have it evaluated.
Pressure. Try changing your shoes to some that are wider in the toes and have a lower heel. It sounds like your shoes are tight and pressing agains your toe.
Numbness in toe. You should avoid wearing those high heels for a while and if the sensation on that toe does not return, then you need an evaluation by a podiatrist.