Instead of using credit card, approach people with money to invest with you. People with money would love to get into crypto. If youve built mining rigs, you can put together a simple business case.
Its always dumb to use your own money, its even dumber to use money you dont have (credit). Use someone elses money and give them a nice ROI while you get a decent returns as well. Spread the risk and increase your profit.
This is horrible advice.
If you make money, you will need to split your profits.
If you lose money, depending on who these people are you will either have to give them a refund or risk losing a family member/friend.