If you spend some of your free time reading some of the other posts here you will learn that almost everyone has gone through what you are currently going through, a natural response. With an fev1 of 89% and you are sensible to follow a few rules and a change your lifestyle then you may be able to to see your great grandchildren.
The "NEW" you should
Stop smoking (which you have done, well done for that).
Take your medicines as prescribed and at regular times.
Eat a healthy diet maintaining a healthy BMI (at the upper end of the scale).
Drink plenty of water.
Your secret weapon, exercise and more exercise, the more you do, the more you CAN do. When you start to get out of breath keep going and use what is called "pursed lip breathing" you can find instructional videos on YouTube for pursed lip breathing. Keep the pace of your exercising so that you are moderately out of breath. You will soon find that you can exercise for longer and harder.
Learn to be able to relax at will, getting anxious is very bad for breathing, if you get a panic attack you will need to be able to relax and slow down your breathing to regain control or you may end up hyperventilating. Stop worrying it will really make you ill.
You are a very, very lucky lady, you have found out at a very early stage, so early that you will only notice it if you get a chest infection.
I was diagnosed last year with an fev1 of 37% and could only walk 35 yards, but with regular hard exercising daily, my fev1 improved to 50% in March this year, I can now manage 5 miles, I still work full-time and I'm 66 years. You have so much going for you in your favour, you are young and half my age. Are you going to let an old man have the better of you? No, of course you are not. Are you going to let this rule your life? Again no you are not.
Take care and carry on posting.