Hii Doctor...i Have A Problem Of Dandruff From Last 3-4

hii doctor...i have a problem of dandruff from last 3-4 months. i am using head and shoulder anti dandruff shampoo but it is not that effective. i have flaky scalp and also hairfall..i have also applies lime with coconut oil but i didnt see any improvement...so please suggest me a good shampoo to get rid off dandruff ,dry hair,,flaky scalp and hairfall...