Managing Anxiety: A Vicious Cycle

I can't seem to control my anxiety. People around me assume my anxiety works the same way as theirs but idk if it does because they haven't been through what I have. They tell me to ride the wave and not give in or let anxiety grow. But it feels so huge. More like a wall that I have to walk through. I panic over the smallest of decisions, and if there's one little thing that I don't understand, then I get overwhelmed and say no to everything, cancel everything and hate myself for it later. Then I feel better and make a bunch of little decisions that I know anxious me will hate and cancel again. It's a vicious cycle, it's like two people trapped in one brain fighting and I can never find any kind of balance. The switch between the two happens so fast and completely at random from what I can tell, one minute I can take on everything and the next, I'm having a breakdown, an attack from within that always feels like it'll be the last thing I know. It seems like extreme mood swings but it's constant, worse the last few months, and that switching back and forth is a compete change in the way I think and it's horribly exhausting. I'm in therapy but it feels like the same thing every visit. I'm not sure what will help me manage this or even where it's coming from? I just want to be like my family for once. I just want to be able to do what they do and not confuse them so much.😔🙃