Would be able to guide you better after seeing the pictures of your beard area, as density cannot be assessed on history. If there was a full grown beard earlier, and now you are losing hair, the cause may be alopecia areata. But if the density was thin from begining, then usually medications don't work so well and hair transplant works good in such cases. You can consult online with clinical pictures for better assessment.

Yes .Don't worry...... Specific medicine available for good growth... Treatment depends on the severity..Do direct online consultation for detailed prescription by sending photos.