With only $5,000 to trade, you have no business trading.
The amount one should risk per trade is dependent upon a few factors:
1. The expectation per trade of the strategy being traded
2. The desired rate of return
3. The trader's tolerance for risk
The only way to really figure out how much to risk is to do some rigorous testing of the strategy you intend to implement. You need to find out what percentage of winners you will likely have, the ratio of dollars per win to dollars per loss, the average losing streak and the worst losing streak.
Once you you can figure this out, you can crank up the numbers to see how much of a drawdown will go with the desired rate of return. For instance, can you tolerate a 50% worst drawdown in exchange for a 25% compound annual return? The typical trend following commodity trading advisor is willing to accept that type of ratio.
The 1-2% rule is a typical risk per trade suggested by some people familiar with the Turtle trading system in the futures markets. That level of risk was reasonable back in the 1980's when the system was originally taught, but not generally applicable now since the system has deteriorated. Many people who don't really know much about trading then just spout off that rule because they heard it from someone else.