i can understand how a dream about the past would shake the foundation of your day. perhaps some mindfulness would take some of the edge off of it. i do a visualization where there is a door at the front of my mind and one at the back of my mind. the thoughts come in one door and out the other. the only mind i pay to them is to shove them through from one side to the other. i think it is the emotional attachment to the thought that bothers me so, so i dont dwell on it. i just acknowledge it long enough to say that that is something that needs to pass on oiut the back door. i may be pushing it through all day but as long as i see that i am pushing it through i dont attach to it. hope this helps.