The worst thing you can do for yourself is start to label your happiness, imagination or ideas as manic. Hypomania is happiness for normal people. Them doctors just had to call it something else in the context of a disorder. Same goes for your depressive feelings. Eventually, you will learn some definite signs, like things that you find yourself doing or experiencing only during a mood episode. (Like for me, posting here! I only participate in these types of forums when I'm not quite right.)

Being happy, spending a bit too much money (not the examples given) having plans to study abroad etc is good! Enjoy it.

Feeling sad, unhappy, lonely and even hopeless at times, part of the human experience, accept it.

Not everything you experience emotionally is your bipolar (if you have it) or that your ideas are unrealistic, so what if they are? You're not going to get anywhere wondering if it is mania or depression all day. That's a trap. A trap I tell you!