So for those who don't know, I'm 13 years old and I have GAD (not diagnosed, and this is one of the main reasons why, but I'm 100% sure I have it because the symptoms are too similar)

Okay, so with almost 3 months of struggling with an anxiety disorder, all I've ever done is self help, no support (some but not very much) and no therapist. I've been struggling all on my own.
And while the self help has helped me quite well, I still feel like something is missing, like I'm not doing something right. I decided I had enough of struggling on my own and self help and that I needed therapy and someone to talk to in real life who had experience/ a therapist.

Half an hour ago, I purposely started showing scenarios of my anxious feelings and thoughts to my mom. She noticed, and we had a little talk about it. But I didn't even start explaining and she started yelling, telling me how much I stress her out with my anxiety, asking me why I can't be normal like other kids, why can't I just shut my thoughts off and think positive.
I told her it's not that easy and at this point I was scared to even tell her I have a disorder. She started telling me how I will end up in a mental asylum if I continue thinking like this. This triggered my anxiety even more and I started tearing up but I had to turn my head away cause it would only make it worse.

Don't get me wrong, my mom is the best mom I could ever have and I love her to death, but when she out of all people doesn't support or understand me when I have this problem, I get really hurt. Also, I'm 13, I shouldn't even be dealing with this on my own (I'm not trying to play victim here, but I have to be honest)

Honestly, I feel like she's in denial and not very informed about anxiety disorders and panic attacks, because she told me only crazy people think so negatively and anxiously and that it isn't normal. Plus the fact that I live in a country where this isn't very common and for my age neither. So this is the main reason why I can't go to a therapist, because if she reacted this awfully to me just telling her...then there's no way she will take me to a therapist.
As for my dad, he doesn't know about any of this and I honestly don't want to bother him about it.

Please don't think my mom is abusive, because I know she isn't, like I already said, I couldn't wish for a better mom. I just feel like she doesn't understand and is probably overwhelmed with my and other problems. But I really can't convince her because she gets so frustrated and emotional because she cares about me but probably doesn't know how to help me and is in denial.

So can please any of you who had CBT or went to a therapist for GAD, give me some of your advice? I really wanted to try CBT but looks like I can't. If not, anyone know any self help CBT guides? Any help is appreciated, thanks.