You may confuse the tidings of a bipolar disorder with external effects like co-workers. I think one of the most important part of dealing with depression is stopping to blame external circumstances, other people and even yourself. Come to think of it, stop blaming anything or anyone (like in buddhist phiĺosophy)!

Another part is to objectify suicidal thoughts. They are both extremely real, but caused by the disease and distorting reality. It's very easy to find reasons for suicidal thoughts, but they are hardly ever "true".