BPM of 42 and fluttering feeling in the chest, should i be concerned?

Prior to this, i have had visits to the doctor concerning my heart. I was diagnosed to bulemia nervosa (no need to tell my how horrible it is, I am completely aware and going through treatment currently). He was concerned qbout my BPM because due to lack of nutrients and the strain of purging, my heart beat per minute was around 52. I usually monitor my BPM daily. I was laying in bed and begun feeling fluttering in my chest. No pain, just a consant very severe feeling of fluttering which is extremely uncomfortable. I took my BPM being that i knew it was an issue and it was 42 and i noticed when i put my hand to my chest i could feel my heart beating very strongly. I'm not a conditioned athlete or anything and this has happened before, but not this severely. Can anyone tell me what's going on and if there's anything i can do to relieve it? Thanks so much. xx