Is It Safe To Take Betaserc For Seven Weeks?

I m 22 years old and I was diagnosed with vestibular neuritis 5 weeks ago after a sudden attack of non stop vertigo, vomiting and my balance went off. The ENT prescribed dizinil for 10 days, then betaserc 16mg for 3 weeks: 3 times a day for a week, then the dosage lowered to twice a day for 2 weeks. After my last checkup appointment he told me to keep taking the betaserc for 7 more weeks because two of the symptoms are not gone yet. The first is that when i turn my head from right to left my vision is blur, but when i turn my head from left to right its all good! The second symptom is that I feel my head rocking when walking its getting better but still whenever I walk or do any cardio exercise I feel my head is rocking. Is it alright to keep taking the betaserc for 7 weeks? And should i stop taking it if the symptoms are gone before the next checkup in 7 weeks. Shall i go do any tests to know if its a vestibular neuritis or something else? The only test he did was a balance test, and he diagnosed me based on the symptoms. Thank you