The low blood pressure in your case may be due to the medicines you are taking. Hence you may stop taking all BP medicines for a while and keep monitoring your BP at regular interval. They can be restarted gradually as BP starts rising again.
Regarding your second query, low BP
in a healthy individual is not of much concerns till there are symptoms like dizziness
, light headedness and feeling of weakness. However, in a person with any kind of ailment, BP below 90/60 demands that patient consults a physician. In your case, if BP does`nt normalize after stopping anti hypertensive medicines, please consult your physician.