When your account got suspended by Twitter, check your inbox for account suspension email by Twitter and follow the instructions there. Account locking out issues happens regardless of the app you use, whether you use the Twitter website or an application like Circleboom.
If you didn't receive an e-mail, you can also appeal for suspension here: https://help.twitter.com/forms/general
Disappearing of all of your friends happens when Twitter temporarily locks a Twitter account. Once the account owner proves, all friends and followers show up again on the profile page.
Twitter suspends users’ account time to time when they do an aggressive follow churn as mentioned on Circleboom and Twitter Rules https://help.twitter.com/en/rules-and-policies/twitter-following-rules "What is aggressive follow churn? If you decide to follow someone and then change your mind later, you can visit the person’s profile page and unfollow them. Aggressive follow churn is when an account repeatedly follows and then unfollows a large number of Twitter accounts. That may be done to get lots of people to notice them, to circumvent a Twitter limit, or to change their follower-to-following ratio. These behaviors negatively impact the Twitter experience for other people, are common spam tactics, and may lead to account suspension. "