The more times i take my blood pressure in a row, the more it keeps going down. does accuracy go down if i take it too much?

No: Many things affect our blood pressure. As you've seen, BP is always changing; I've seen it change over 20 points in a minute. The very act of taking one' s BP often raises it so the reading you get the first time is probably higher than it would be if you were not measuring it. As you take it more you tend to get more relaxed, so later readings are probably more reflective of your baseline level.