Medicines like Ashwagandha or any stress relievers are not meant to be taken whole life. You need to develop immunity within your body.
Next Steps
Ashwagandha in powder form is different in action than in lehyam as lehyam got many more herbs in addition. It all depends on your body constitution (prakriti) and your present state of illness that what should be given to you.
Health Tips
Please don't do self medication. Meditate twice a day, Sleep well & Stay Positive.