nocturnal panic attacks in children ?

Please help i dont know where to start ? My 11 year old son for the last 3 months has been randomly waking me telling me he is going to die , having a heart attack and crying to the point where i cannot calm him down , i thought it may have been night terrors/ puberty but i dont think it is as he is awake and aware and can remember the next day usually i remain calm after the inital shock of being told he is dying :/ and then he will sleep but wake several times a night resulting in him not getting the rest he needs and fearing all day that it will happen again im not sure what triggers it at all it just happens sometimes everynight for a week and then sometimes there is a gap between i was hoping some mummys here have experienced this and could give me some tips ,guidance etc i would like to avoid the doctors right now as they will probably just give him drugs to sleep and id like to avoid that . should i obtain counselling or anyone have any tips on how to cope ? thanks so much