Hello
You mentioned you have tremors only in left foot that suggests there might be some muscle weakness in your leg and foot muscles.
Sometimes one or less
vitamin deficiency also causes tremors in yor body.
Lack of water intake is also a reason for your tremors.Do you have cramping in your leg???
Next Steps
Start strengthening exercise under proper observation .
Sit with supported legs.
Health Tips
If it continues then consult your physician first.