This is the place to vent! Welcome OP.

I can relate to a lot of what you're saying. Actually, in some ways our family histories run parallel. It seems like your dad is mixed Dutch and moved to Sweden later? My dad is also a mixed Dutch national, but he moved to the U.S. Growing up, I remember how frustrating it was to constantly play through this conversation:

"So, where are your parents from?"

"My mom was born in Taiwan, and my dad's from Holland."

"Really? He doesn't look Dutch."

Yeah... I'm aware... It gets old.

Like others here, I've wondered if it would be simpler to be 50/50 or monoracial. Sometimes yeah, it seems it would be easier if my family's nationality, ethnicity, and appearance all lined up. But then I think of all the amazing things I've absorbed from the many cultures I interact with, and I wouldn't give it up for anything.

The fact is, OP, your identity will always defy easy categorization. You can't be put into a tidy little box. That can be very frustrating and it can lead to misunderstandings. However, there's a lot of strength in defying simple categorization.

This sounds cliché, but don't let others define you. Only you get to decide who you're going to be. If you're proud of being Somali, keep exploring that side. It's not like because you're ethnically 25% Somali, you can only explore that a quarter of the time or something like that; it's just not that simple.

Finally, if the "What are you?" question gets old -- have you tried being direct with the people asking you? I've experimented with politely telling people that this comes up a lot, or simply saying that I didn't feel like talking about it. It was weirdly empowering. I wouldn't recommend being rude, of course, but part of the strain of this question (for me) is the feeling that I have to explain myself to someone. Knowing I have the power to refuse feels great.