Hello Vidya,
BAMS is Bachelor of Ayurvedic Medicine and Surgery and ayurveda is ancient Indian medicine hence the foundation language is obviously sanskrit, the medicinal names will be in sanskrit and during the course ,in the first you will have to take up sanskrit compulsorily. It is perfectly fine that you had your early education in English. But if you are interested to take up this course and become an ayurvedic doctor , your gonna have to develop the interest for sanskrit and learn it now. Therefore to answer your question, not difficult provided you can master sanskrit now.
All the best.
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