Doctor diagnosed me with telogen effluvium due to "stress" , he told me to use elocom mometasone furoate lotion 0.1% ,is this used for te treatment?

It does not hurt: You need to remove the underlying cause . If it is due to stress you avoid stress. The lotion ordered for you does not hurt since your body secretes corticosteroid to the blood stream when under stress this lotion also contain corticosteroids so more corticosteroid is better in a sense but without it you are not going to loose anything significant.