Instead of using credit card, approach people with money to invest with you. People with money would love to get into crypto. If you’ve built mining rigs, you can put together a simple business case.

It’s always dumb to use your own money, it’s even dumber to use money you don’t have (credit). Use someone else’s money and give them a nice ROI while you get a decent returns as well. Spread the risk and increase your profit.