No one said that you, specifically you, were a terrorist. The closest that comes is "that's what a terrorist would say."
Which is both a comedy and accurate response. Because "that's what X would say" is a very common comedy response to any denial. But in a very accurate sense, yes, Terrorists do not see themselves as terrorists. They use words like 'patriot' and 'freedom fighter' to describe themselves.
So. If a statement like "MAGA is a terrorist group" feels like you're being labeled a terrorist, that's you applying meaning that is not in the text.
However, the MAGA movement is willing to use violence against civilians to achieve political goals. Voter intimidation at voting locations by hanging out with guns. Jan 6th insurrection. Claiming that there will be a civil war if the candidates they support lose.
This is the literal definition of terrorist.
If saying that MAGA is a terrorist group causes you to feel that you're being labeled a terrorist, you should reconsider your affiliation with that group.
And I understand that if you are truly a 15 year old girl, you're likely surrounded by parents and other adults that tell you that you're part of that group (because they are). I would suggest you take the time to consider your values and are they really represented by that group.