hat advice could you give? Slowly scale up bit by bit instead of switching immediately?
I'm not sure when or if you're going to read this as you haven't been here since the moment you started this thread; however, it would seem from that passage I quoted from your initial post that you already sense that you know the answer.
Instead of starting with a small capital and then adding more capital after some success, start small and run that stake up.
Start with $500 or $5000, whatever your small account comfort level is. Make that the one and only contribution to your trading account from your current resources. So you want to trade a seven figure account? Then run that small starting stake up to seven figures. If you you have an edge, you can run up even the smallest margin to a fortune. If you have an edge.