Some people have the habit that pull their hair, eyelash when being nervous. They usually relieve the pressure by doing this. However, it is not a healthy action, which could cause hair and eyelash loss.
Besides, it also could damage our eyelashes when pulling out eyelashes, or causing more complex and dangerous problems. Therefore, if possible, high recommend you to stop this unconscious activity.
You can keep your hand and brain busy when feel nervous. Or you can also ask your doctor for professional advice.
For the eyelashes that have fallen off, you can take careprost bimatoprost serum as a remedy. Which could help you regrow naturally longer thicker and fuller eyelash within few weeks. Just feel free to take a try.