I have a large one from my grandad's funeral about 12 years ago. I rarely ever feed it and it just grows and multiplies very well. In the summer I put it outside on the porch so it can get more light. When the leaves on mine droop it normally means that's it's dry. They're very forgiving plants. How strong was the miracle grow? I'm sure if it's not too strong it will recover. You may want to post this on the houseplant forum if you need more help.

All I can suggest is tht you water, water, water it, a few times a day, to try to dilute the miracle-gro.

I don't know if I'd risk pulling it up and washing off the soil and giving it some fresh soil. Maybe someone else here can comment on whether that would help.

Hope this works out. I know it's tough when you have an emotional tie to a plant.