Quality of life, for you and your family, is worth more than gear in the music space.
On paper, low/no interest credit cards can be beneficial, and some can take advantage of that. That “some” are people who have the available reserve of cash to pay the card off if the anticipated income falls short. Credit card companies are a multi-billion dollar industry… they didn’t get that way from giving away money below market rate. Think of how many have to fall short of payback-in-time for that offer to be profitable for them, and you’ll realize how Teflon-slippery that slope must really be.
Hang on to what matters, use the rest for what also matters, but isn’t music. Missing a guitar or amp you sold doesn’t mean selling it wasn’t the right/best thing to do!