“What do counselors do for anxiety?”

There are many theoretic orientations and interventions for anxiety, and it depends on the specific person and the type of anxiety. Examples of therapies are CBT (cognitive behavior therapy), mindfulness training, ACT (Acceptance Commitment Therapy). If there are OCD aspects or others, more specialized therapies might also be indicated, e.g. ERP (Exposure Response Training).

Identify how it feels in the body, how anxiety changes in varied environments, and what patterns of behaviors, thoughts, and feelings from childhood are still present as an adult. Utilize coping skills to assist when anxiety is activated so the person learns how to manage their life rather than being managed by anxiety.

Teach relaxation training and mindfulness, encourage healthy activities such as exercise and address distorted thinking. Sometimes referral to a psychiatrist is helpful.

Counselors will help you understand where your anxiety is coming from and what to do about it. They will often help you learn specific techniques to help manage both your physical symptoms of anxiety, like racing heart, shortness of breath or nausea, and your cognitive symptoms like the thoughts you have and how quickly they are going through your mind. This will often take several sessions to understand what triggers and maintains your anxiety, learn different techniques, and practice them with the help of your counselor.

Therapists typically do cognitive-behavioral therapy for anxiety which is a systematic way of challenging irrational thoughts while also developing behavioral strategies for managing anxious symptoms. Melanie Sholtis, Psy.D. Licensed Psychologist (240)-210-9003

cognitive-behavioral therapy (CBT) is highly effective at treating anxiety disorders. Through CBT, psychologists help patients learn to identify and manage the factors that contribute to their anxiety.

Depending on the type of anxiety you're experiencing, there are many many effective evidence-based treatments that can help decrease anxiety. CBT (cognitive behavioral therapy) is the treatment of choice for anxiety. It may involve helping you identify patterns of maladaptive cognitions, for example black and white thinking, catastrophizing, overgeneralization, personalization, etc. these are general ways of thinking that can lead to ongoing anxiety. Once the patterns are identified you would learn how to challenge and/or reframe them. Another way of working with anxiety is recognizing the difficulties with tolerating uncertainty and learning to live in the moment with mindfulness techniques. You might also engage in ERP (exposure response prevention) which is tolerating specific things that make you anxious beginning with the things that make you least anxious and working our way up. ERP isn't about throwing you in the lion's den with your most feared situations, but first teaching you relaxation techniques. There are also grounding techniques and meditative skills. ACT is a big one which involves allowing and accepting. There are DBT skills that complement this with radical acceptance skills and recognizing that which you have control over. I'll leave you with this:
Imagine a 5 story building on fire. See the flames waving violently out the windows of all floors of the building. Every floor is engulfed in flames. Can you picture it? You're standing there in front of the building tasked with the responsibility of putting this fire out. You have a hose in your hand, and the water that is coming out of your hose is going drip... drip... drip...
That's anxiety. What you actually need is the entire fire department and all the engines with huge hoses and shooting water to combat these monstrous flames. Anxiety is your perception of the problem being so out of control and your resources to tackle the problem being completely inadequate. "Perception" is the operative word here. It's a thinking problem. The anxiety is the feeling that gets created from the thought.

See this link...
https://www.helpguide.org/articles/anxiety/therapy-for-anxiety-disorders.htm
and
https://www.apa.org/topics/anxiety/disorders