Is slow action or reaction about things is related to low blood pressure?

Possibly: Usually reaction or activity is more related to hormonal (example thyroid and blood glucose levels), general health (age, weight, exercise status, presence of sleep apnea, anemia/liver/kidney issues), and cerebral-cognitive issues (level of wakefulness, depression). A good review by your doc might help if the problem is severe enough. BP and med issues (ex-treating htn), could be involved.