Need to optimise(lessen cpu load) indicator and add customisation features

Attached is the indicator. When loaded even on one chart it overburdens the computer's cpu.

Optimisation: 

1) need help to optimise it.

(it is a simple calculation but it is more cpu intensive than running a video game: which is unacceptable)

I also want to add customisation.

The indicator is centered around the formula of

pivot price: (past 3 periods high + past 3 period low + close) / 3

second number: (past 3 periods high + past 3 periods low) / 2

differential: pivot price - second number

pivot high: pivot price + differential

pivot low: pivot price - differential 

plots the 3 lines consistently through history.(easy for eyeballing)

i need to add 3 customisation as follows:

1) need to be able to switch to other timeframes/periods. instead of calculating over 3x day(period).
have 3x monthly, 3x weekly, 3x 4H(4hour), 3x 1H(1hour), 3x 30m(30minute), 3x 15m(15minute), 3x 5m(5minute), 3x 1m(1minute)

2) need  to be able to also specify how many periods to consider. 

i.e. a) if specify 8 periods. it will be pivot price: past (8) periods high + past (8) period low + close / 3 and so forth.

3) option also whether to print real time and view historically the 3 points(pivot price, pivot high, pivot low) calculated.

i.e. instead of  waiting for the end of the period to print the next, print the next now. usually on open of a new day will the previous 3 days pivot will be shown.
but now. during the day i can see that the indicator assumed current price is the close price for the formula.
it then prints/shows the 3 lines. also shows where it has been(where previous bars close price is the close price calculated by the formula)

Regards,

nico