What to do when you genuinely don't understand anything about taxes, yet are apparently expected to pay them for your Bitcoin?
If I cannot understand the laws/regulations, what am I supposed to do?

A fairly widespread legal rule is that ignorance of the law is no defence.
If you don't understand how the law applies to your situation, you are expected to seek help from someone who does.
You can contact your local tax authorities and ask them, or you can pay for advice from a tax-expert such as an accountant.
All this applies to Bitcoin as much as it does to other forms of money and other assets or investments.

I'm obviously afraid of sending them a letter and asking about my specific situation, because then they will know that I have coins and probably start pestering me about &quot;unpaid taxes&quot; or something.

I wouldn't have such concerns. We all like for hospitals, roads and waste-collection  to exist and be organised by government and paid for by all of us with any significant income or with assets. If you prefer, pay a tax expert for advise.