it probably takes around 10 years to go through most of teh economic conditions which define markets - bull / bear / sideways etc
However you say your strategy is not successful ! - dump it then ! 
The length of time you should test a trading strategy depends on several factors, such as the type of strategy, the time frame youâre trading on, and the number of trades it generates.
Here are some general guidelines to help you determine an appropriate testing period:
- Sample size: Aim for a minimum of 100 trades to get a reasonable idea of the strategyâs performance. A larger sample size, like 200 or more trades, is even better as it helps to reduce the impact of outliers and provides more reliable results.
- Time frame: If youâre trading on a shorter time frame, like minutes or hours, you can test your strategy over a shorter period, like a few weeks or months. If youâre trading on a longer time frame, like daily or weekly charts, you should test your strategy over a more extended period, such as several months or years.
- Market conditions: Itâs essential to test your strategy across various market conditions, including trending, ranging, and volatile markets. This will help you understand how your strategy performs under different circumstances and make necessary adjustments.
- Consistency: Ensure that you test your strategy consistently, sticking to the same rules and parameters during the testing period. Changing your strategy mid-test can lead to unreliable results.
- Performance metrics: Monitor key performance metrics, such as win rate, risk-reward ratio, and drawdown, during the testing period. This will help you assess whether the strategy meets your expectations and risk tolerance.
There is no single answer to the question of how long you should test a trading strategy.
The key is to have a big enough sample size and test it in different kinds of market conditions to get a full picture of how it performs.
Be ready to change and improve your strategy based on the results of your tests, and remember that past performance is no guarantee of future performance.
Give yourself 6-12 months of using that trading system.
First 3 months or Q1, spend that on back testing, forward testing and live demo trading.
Back Testing - theory
Forward Testing - Using trading simulators to get the feel of placing a trade
Demo - trading live using a demo account
Q2 or the following three months, trade a small live account, or a prop firm.
Put your system to the test, see if you can double that small account within 1 month. Prop firms, see if using your system can pass you prop firm challenges.
This will be enough time for you to collect results, reflect on the progress and see where youâre heading with the system and if you should continue using it or not.
Use this data as information to tell you what went wrong, what went right.
Donât worry about market conditions, in fact this is great if the market is not good condition because you get to see how your system behaves and how you can adapt to the market conditions.
Donât dwell on hearing too many opinions as that could cloud your judgement, if you can close the thread before it gets out of hand.