The Course of Miracles teaches you don't have to purify your thoughts to get rid of anger, guilt or other disturbing feelings. Pretending your positive without sorting through the other stuff isn't helpful. People don't attack you with words. You only imagine they attack as a reminder that you're not dealing with emotions you put aside. You made past decisions yourself, and you can decide differently this time. It gets easier to think positively as you take responsibility for what you believe.
Real situations are those where it doesn't matter how things turn out. It doesn't matter what happened in your past, or what you thought before. The time comes where you realize that all your perceived problems are your own projections and hallucinations. These issues come up repeatedly as second, third, fourth or whatever chances, simply to give you opportunities to learn and rise above them.
People will say they aren't in your life to change you. You may think you don't enter the lives of others to change them. Yet, relationships and others situations come up because you're meant to learn from them. Are you optimistic about each one? You have been drawn to conditions because you have decided wrongly before and you aren't yet on a level of inner peace. Develop gratitude. You need your own appreciation to move ahead. Real positive thinking comes from listening to yourself.