@mostafamahjoori, It's good that the breathing exercises are helping even if a little. That means progress! It might take some time for the body to adapt to the exercises and I think you may see some more improvement.

Have you looked into other ways to deal with anxiety? There is an effective method of dealing with anxiety and other issues called Cognitive Behavioral Therapy. I believe this may help reduce your anxiety over time, and something I would suggest looking into. There are online sessions to learn CBT, and I think would be worth a try!