Need Advice on Starting Capital. First time investing

Hi everyone!
I’ve been studying forex for the past 3 months and developed a trading strategy that seems fine for me. I’ve been testing it on demo accounts and seeing consistent results, but now I’m ready to go live and honestly feeling a bit overwhelmed about how much to invest initially.
My situation:

  • Developed a swing trading strategy focusing on EUR/USD and GBP/USD
  • Maintained 8% monthly returns on demo
  • Have $15,000 saved for trading (money I can afford to lose)

My strategy:

  • Focus on major pairs during London/NY overlap
  • Risk 1-2% per trade max
  • Hold positions 2-5 days typically
  • Use technical analysis + economic calendar timing

My question: How much should I start with?