Honestly I think in some cases it may be a case of going to far. For people like us we have to balance our emotions, they swing either way. So it's likely a matter of knowing when to ease up on the positive affirmations, as some people may be more or less sensitive. It's also a case of knowing what you should replace your thoughts with and how to present that information to the rest of your mind. As phrasing is also very important when communicating with yourself. A large part of our problems come from a miscommunication with our minds, so I keep things simple. Colors work really well for changing perspectives "moods" as well. Something that contacts the skin will help you remember easier. A light shade of purple is very soothing, while yellow can be uplifting. You can use memories "childhood ones for me" to help it along and try feel the warmth of color. Use your peripheral vision, to highlight as much of the color you want. I normally use purple, but any color will help you notice all the colors more. This does two things, it draws you out of your head more and the colors help change your mood over time. Personally I found none of them work entirely on their own, but when using several techniques together you can efficiently control your emotions.