Being unfollowed or unliked is a part of Social Networks. You can’t run away from this and you should not take this personally. But at least you can find out who unfollowed you on Twitter with the help of various tools and work on specific areas to decrease your unfollowers.
Unfollowers.me lets you know who has unfollowed you on twitter via email or tweet notification. You can also use advance features such as block or unblock any users easily from your dashboard, compare users, autofollow your followers, send DM to multiple users, invite multiple users to follow you & many more.