Add a simple money management function to my EA

I have a multi currency EA that needs to add a simple money management function.

Current function: Lot per balance - for example trade 0.01 lot for every 3,000$ balance, So $10,000 balance will trade 0.03 lot for every signal.

I need this money management to have an auto scale True/False option

Lot per balance Only Up = True: don't decrease the lot size when balance is reduced. So if balance increases from $7,000 to $10,000, EA trades from 0.02 lot to 0.03 lot, but if balance decrease from 10,000 back to 7,000 it doesn't scale lot size back and still trade 0.03 lot.

Lot per balance Only Up = false: increase and decrease lot size for new signals in update of current balance