An Announcement,
Instagram is deleting the accounts of Users who use Urls and Web Domains used on Comments.
IF YOU WANT TO USE AN URL YOU HAVE TO ASK PERMISSION TO INSTAGRAM TEAM ACCCORDING TO RECENT NEW TERMS OF USE.
“Instagram is a place where people can share beautiful photos of their lives, and when you engage in self-promotional behavior of any kind on Instagram it makes users who have shared that moment with you feel sad inside. This guideline includes repetitive comments, as well as service manipulation in order to self-promote, and extends to commercial spam comments, such as discount codes or URLs to websites. We ask that you keep your interactions on Instagram meaningful and genuine, and note that we are working on reducing comment spam”.
So keep an eye when you comment any links on your followers list… or while changing link in your profile…
A Mail which is received when the account gets disabled/deleted
User Deletion
If your Instagram account was deleted utilizing the secure Account Removal page there is no way to restore your account. You can create a new account with the email address formerly associated with your deleted account, but you will not be able to utilize the same username.
We suggest attempting to create a new account with the same email address in order to determine if your account was removed through the Account Removal page, which would have required knowledge of your password. We cannot restore your account, even if your account deletion was not authorized, and suggest you use a private and secure password going forward.
Instagram Disabled
If you have violated our Community Guidelines or Terms of Use on any account that you own your account is subject to removal and your access to Instagram may be revoked without warning. There are no exceptions to this policy.
We’d suggest that you review the Community Guidelines carefully along with the content posted to all accounts you have created. If you do not believe any of your accounts have violated our Guidelines or Terms you may refute your account’s status by completing this form.
It is important to note that if we are able to locate an account that was removed for violating our Terms or Guidelines we will not respond to your request.
@imranakbarin
Ref:
Imranakbar's Blog 
My instagram keep deleting when I follow a lot of people a day and I dont know why it keep doing that please gove me a anwser