Create MT4 EA to use Martingale System using lotmultiplier OR preset lot sizes that I set

My current situation is I have an existing EA done by an ex-freelancer who is no longer active. I own the files but I would like to add some functions to it. Also, it seems to have some zero divide error which is causing the martingale not to open new trades when it is supposed to so I am trying to do up a new similar one with some additional settings.

Here is how it should work:

1) Upon launch, I should select:
a) whether I want to do buy or sell or both.
b) if UseMultiplier is TRUE, I should set my Lots and LotsMultiplier factor,
c) If UseMultiplier is FALSE, to trade based on my pre-keyed LotsPosition and MaxOrder level (if i only key in 3 lot position and maxorder is 5, the 4th and 5th trade shall follow the last lot position. If I key in 10 lot positions and max order is 5, it should stop opening after 5th lot position)
d) It should allow me to set what is my PipStep between trades and if I amend it halfway through, the next trade to be opened should follow the revised pipstep.
e) It should allow me to set the TakeProfit ratio and to auto adjust the TP for all open trades whenever it open a new trade or whenever I change the TakeProfit figure.
f) It should allow me to set whether I want to continuetrade for buy and sell separately. Ie, if i set false for BUY, it should finish its current BUY martingale cycle and stop opening new BUY.
g) it should show me the current profit (nett of commission and swap if possible) of all BUY trades and all SELL trades separately on screen.
h) it should have a button that allows me to click to instant close all BUY or close all SELL
i) it should not have zero divide error which my current EA seemingly have

So effectively it is basing on martingale to keep opening new trades and close all BUY or SELL when desired TP is achieved, then start a new cycle using the first lot size again.

I am attaching my existing EA for reference since the new EA should work largely similar way and its existing parameter it has are below.. highlighted ones are the ones I am using actively and those others I believe are not much use to me.

ContinueTrade
UseCR
Close Ratio
Takeprofit
Pipstep
MaxOrder
LotsPosition
UseMultiplier
Lots
LotsMultiplier
MagicNumber
EaComment
NoteColor
clrSilver
FontType
FontSize

Any clarifications, please do reach out to me.