According to the data you provided, the reason for your symptoms might be anxiety. The anxiety might be caused by extensive physical or psychical overload. For example: not enough sleeping, continuous tension at work or at home, too much intake of substances that affect the heartbeats like coffee. Maybe you can try to notice if any of these factors are related to your lifestyle.


The feeling of anxiety makes you more sensitive to the changes of the heart that might be within normal limits. You did not specify how often you register skipping heart beats. You might ask your doctors what is the upper limit of skipping heart beats within 24 hours measured with the exact brand of Holter that was used. Then do the following math: divide the beats per minute from your ECG or the Holter with the number the doctor told you if a percentage was given. The final result will show you how often you can expect the heart to skip and not to consider it pathological.


Example: 75 (heartbeats per minute) / 1 (percent upper limit) = 75
This result means that you can expect 1 skip of the heartbeat in more than 75 heartbeats and it would not be considered pathological.


Important note: the frequency of the heartbeats changes when inhaling and when exhaling. The transition between these two phases is sometimes recognized as a heartbeat skip by inexperienced non-health-professional persons.
Also, you might want to try relaxation techniques, yoga, or something else. You might also consult a psychotherapist. Behavioral therapy might turn out to be a good solution for your problems.