Well theres 2 types of anxiety. 1 is the anxiety that is natural from a immediate threat. I don't think there is anything immediately threatening you? The second is this vague form of anxiety that comes about when humans dwell in the future and imagine outcomes. That's also a vague form of fear...
I used to have this problem BIG TIME. It was so painful for me that I was thinking "if I have to live like this for the rest of my life I will end it." Yet I didn't want to end it! I just felt like aww fuck shit is sooo bad right now
So this is how it ends imo. Stop thinking about insane outcomes like school or what if what if what if...
Be fully present right now, where you are! In this very moment there is probably no issue except for your anxiety, and if there is a problem, deal with it, but you can't deal with problems of the future! You can only deal with problems right now.
Also I found that there was a chronic tension in my chest that I was too afraid to let go of. It was this throbbing red feeling that I now think is a stressing of energies. It was as if I had my hand clenched for a very long time and forgot that I was clenching my hand, and then my hand started to hurt, but I couldn't tell why and never stopped clenching my fist.
I think if you accept your pain and stop trying to distract yourself from it, focus on your inner body with full awareness, stop dwelling on your past and future, let life flow rather than trying to rigidly control it, and look for muscles/energy in your body that you are clenching and can release that you will feel much much better.
One thing that I found is truly amazing is that if I am very very present and mindful, my body and anxiety and depression start to lift within 5 minutes. They don't just vanish, but a peace engulfs me that is stronger than the pain. Also I can tell that those afflictions do slowly ware away when I am present. I think that is because when I am present, I am not feeding the addiction of worry/self pitty/self hate/self clinginess. When I am present and mindful, its as if I am watching myself rather than being myself and this instantly makes me feel better because the drama is no longer mine, but simply just drama. It allows me to relax at a deep deep level because as long as I am mindful, I feel safe.
To be mindful for me is like waking from a dream. In a dream one just reacts, they don't really have consciousness behind their actions. They could do something in a dream that makes no sense and gets them hurt. When you wake up, you become more careful because things seem more real. Mindfulness is like that again.
Just try it

At first it will hurt real bad because the reason you havn't been mindful thus far is probably because your in pain and don't want to be present. See people are constantly seeking external input because the present is so painful and we are afraid to face it. Mindfulness is facing it and what ever you shine the light on, becomes the light!