Definitely people from your past relationship.....pray and seek help from spiritual leaders who can help cutting off your soul ties with your ex as well....
Check out Neil T. Anderson book as in his books, he can guide you to pray for yourself and others.
I have been reading his books and pray consistently for myself to set free from any darkness. I found his books very helpful.
Don't associate with people from your past anymore....you need to let go of those memories and don't let anything to trigger your memories again. You have made the mistake, yes me too. Now you are made brand new in Christ Jesus, and you are a new creation. You do not need to hold onto your old regrets because the blood of Jesus has ALREADY set you free from the moment you acknowledged Him as your personal Saviour. You need to believe it.
No longer do you need to look back, Jesus has paid for your ransom. You are in Him. You belong to God.
Let go of your past mistake, no looking back. Sing some spiritual songs that your spirit can be revived and refreshed in the Lord again.
May God bless you.