2 months back i had a suffocation attack which had my bp raised to 170/120 (by overthinking what is happening with me). initially i thought it was a heart attack. but all reports (ecg, echo, tmt) came normal. what i guess now it was a panic attack. after that i have a bad habit of thinking am suffocating always. it always resides back of my mind. am losing concentration cause of this. i plug in oximeter in my hand to check breathing level but it always comes 97+. healthwise am doing ok now but how to get rid of this mental blockage. moreover i was regular consumer of alcohol n smoke. now i have quit everything since last 2 months. can this mental obstruction be part of withdrawal syndrome? please advise.