That's spectacularly bad advice mate. No wonder you lost $5k a month. @shienri
Your position size should be determined by your account size, leverage I pretty much ignore since my trade sizes are such that they are a reasonable percentage of my un-leveraged account size.
The problem with MT is the minimum trade size is to big for most accounts. At 0.01 lots on 100 000 unit lot size your minimum trade value on EuruUsd would be about $1 120 or so at current rates. If you have a $10k account that's over 10% of your account value. So obviously that's not sustainable. Few losses and you're out.
To get to a reasonable trade sizes on MT you basically need a $100k plus account. This the primary reason why so many people fail at fx. Read Von Tharps work for a more comprehensive explanation, he goes in depth into this.
One broker that doesn't have this issue is Oanda, where you can do a 1 unit trade or 1.12 or so. I very strongly suggest using them at first. Set the platform to use 1% of available account and take it from there till you are more familiar with the entire process. You'll quickly get a feel for how much appetite for risk you have and then you can determine trade sizes as a function of your draw down. So you make an informed decision.
This process will stop you from making the very basic mistake of trying to trade an account that's completely the wrong size for the minimum trade sizes like Edwin here used to do.