How To Withdraw From Concor?

I am 31 yrs old male, over weight, my father died 2 yrs ago after heart surgery and after a week of his death i felt trembling and heart racing i have done ecg and showed sinus tachy i have done all labs which is normal except for high cholesterol and received treatment for it and now controlled, after this attack it came again and again and feared of death, i have done echo twice normal, stress ecg normal, Multidecteror coronary angio normal with calcium score also normal They prescribed for me lustral and inderal my case improved I shifted from inderal to concor 2.5 mg and lustral stopped, when i try to decrease dose of concor 2.5 to 1.25 i feel tachy and anxious and heaviness in left arm when i receive 2.5 mg daily no problem So how to stop concor 2.5 mg i am on it for 4 months or i will be on it for life, thanks in advance