My struggle with social anxiety and depression

Hi, so I’m just about to turn 15 and am a freshman in high school. I know it’s going to sound like I’m self-diagnosing and I’m just a teen who is being dramatic, but I’m really not. The first part of this post is going to be about my social anxiety. I have an unrealistic and crippling fear of being judged, unaccepted, betrayed and people leaving me. I have been to a therapist and psychologist in which I was medically diagnosed with social anxiety and depression, and it has really taken a toll on my mental health and well being. I love talking to my friends and I am a total extrovert, except for the fact that I cannot meet new people. Anytime I am in a situation where I do not have a friend or someone I know around, I have a complete panic attack. I can barely breathe, my brain starts freaking out and I cannot function. Even when going to my sports meets and things, I know I have people I can pair up with, but subconsciously I freak out and feel a have weight on my chest. I am always worried about my friends realizing that I am not worthy of their friendship and leaving me. I first started having problems making friends in grade 3. I would see the school councillor periodically and learned to trust her. The problem with that though, is suddenly the school had a new councillor for each of the next two years. I had to keep re-telling my story and learning to trust them, which I eventually gave up on as they just kept leaving me. That’s how my trust issues and the stress of people leaving me came from. Every time I started to trust them, they would leave and now I am always thinking that people I value will just leave without notice. I also have mild depression (also a psychologist diagnosis) so I feel like I am never good enough for anyone. I have thought of ending life multiple times, and thinking no one would miss me because my social anxiety makes me think everyone is faking liking me. My therapist says to just “change my thoughts to happy ones”, but it doesn’t work because although I can hear them, it is unbelievable. I cannot show emotions other than being happy in front of people publicly, because I am afraid of them thinking I am weak. I don’t want people to judge me because I judge them, and I am worried they think like me and don’t like me. I usually make friends with introverts because they are the closest people who can relate to me but I don’t like that introverts never want to go out or do stuff because I love to. Again I am totally an extrovert but I’m just afraid of people and their thoughts of me. Thanks for reading if you came this far. It kinda helps to talk online about it as it is impossible for me to talk to others about this in person because of the whole “vulnerability” fear and all. Thank you :)