I don't know what you already do and what your insurance would cover but here's a list of things that helped me tremendously:

1. I have two different inhalers. One for attacks and one prophylactic. Since I use the second one daily I haven't had an attack in 10+ years.

2. Have an asthma diary. Measure your breath a few times a week and take notes. After a while you will recognize patterns days ahead when the chances for an attack might be higher. Medicate accordingly! I up the dosage for the prophylactic inhaler slightly when I see changes (e.g. during allergy season).

3. Breath out! That one sounds stupid, I know. Paraxoically the major problem with asthma often is breathing out, not in. So there are breathing exercises where you learn to focus on breathing out to make way for easier breathing in. It can be as simple as counting to 5 while breathing in and counting to 8 while breathing out with a 2 seconds break before again breathing in. Adjust the numbers for you. It calms your breathing and can even help with an attack (though I would still use an inhaler then).

I also have my lungs screened every two years. Ever since I follow the above list my measurements get better over time even though I am slowly past the "it will heal by itself" age.

Where I am from all the above steps are covered by insurance. I know for example in the US inhalers can be obscenely expensive so step 1 might be a problem. But steps 2+3 are low cost and are still very beneficial. So I hope you can find something in the list that eases your burden.