Friend Activity Hacked

[ugh22]

During the last week, my account has somehow been hacked. Once a day or so, all of my actual friend's activity disappears and is replaced by someone elses! Although it doesn't say I am following any of the people it shows, the only way I can fix it is by going through and following then unfollowing all the random people (who are the same each time, hence I think my account has been hacked). Then I have to go to my own friends and unfollow and then refollow them. Is there some way to fix this??????? 

[ugh22]

Also, I have already changed my password twice and logged out of everything and back into everything. When I log back in, the random person's friend activity shows instead of my own.