Hi Isolda Van Der Meer,

My advice is to speak to your GP. Even a conversation can open avenues to talk therapy, which may help you to understand your low (and high) feelings. Mention your concerns and ask for a referral to a psychologist if you want to talk it out more. There's no need for a diagnosis to go, you may walk out feeling like everything is completely fine.
Talking through your concerns with a professional will help to best understand these emotions and gain further support. It's always hard to judge from just your own perspective.

I am bipolar II and started the process by seeking help for depression. The concept of speaking, knowing I am heard helped me to understand my natural ups and downs in mood which helped to identify and refine the diagnosis to get the appropriate help.

I wish you luck.