https://www.optimismonline.com/app/index.php - track your moods for a period of time and show to your therapists. That would get the point across very well. What you are describing (the metaphor with the skyscrapers is truly powerful, and poignant, too) seems to follow a sinusoidal pattern of ups and downs, without mixed states. Mixed states are the most challenging from the treatment perspective, so it seems that your bipolar is not extra difficult to treat. Also, what you are describing fits the pattern of bipolar misdiagnosed as MDD because you only seek treatment during the low stage. It is very common among bipolar people. Since you yourself just wrote that you reach out when depressed and decide that never really need to reach out for help the rest of the time, make a note of this - you said it and not somebody else - so when next time you start thinking that you do not need help, refer back to your own post and say to yourself: "I better continue seeing the therapist".

Another thing is that when you track moods, you track your subjective perception of your states. Usually, in a low state your subjective perception is correct (in line with reality). In an elevated state, you may not be able to register that you are elevated. So mood journals still can be skewed towards portraying you as mostly depressed. A thid party observer, and especially a professional, can fill in that gap by observing and registering your elevated states for you. Would that be a good enough reason for you to sign up for long term therapy and obtain an accurate assessment of your mood fluctuations over time?