About a week ago I experienced what was probably a major panic attack, purely self inflicted from indulging in cannabis use and alcohol over a 2 day period. I am also 3 stone overweight. During it my heart felt like it was working extremely hard and I began to sweat buckets. This lasted 1.5 hours. I could "feel" my heart in my chest working very hard, at least it seemed that way. My doctor checked me out and said everything was perfectly normal but I'm not convinced. An ECG is scheduled for next week anyway.

My worry is based on the fact that since it happened my heart appears to be beating a lot "harder", the rate is perfectly normal but I can feel my heart beat when I try to go to sleep, I didn't before last week. I also have had a mild headache occassionaly this week. I have had no palpitations. On top of beating harder I also feel like I have a mild lump in my throat and also my heart feels slightly weird, like a very mild instance of the type of feeling you get when you go over a bump in a car. These feelings have remained at a constant level in the week since then, neither diminishing or becoming worse at any stage. I've avoided alcohol and caffeine and other stimulants/drugs since then.

Is this harder beating purely in my head? Is it my nervous system? Is the normal after effect of a severe workout of the heart?

The doctor said it could be stress related. It may well be but I am worried there might be something wrong with my heart.