Generally the way credit works is that they want to see how you use what is afforded to you. If you are maxing out all your credit, it shows you have no spending control on your own without the limit.
Oh... well, 30% is total credit, not per month. That is your total liability (amount of credit you have used to buy things) should be 30% or less of your total limit.
So if you have a limit of 67,000 thousand among 3 credit cards. Your total amount of credit used (when you buy stuff it's used, when you pay it off it's not used) shouldn't be more than 22,000 dollars at any given time, including when interest accrues (which is close to 30% so you should just pay that thing off anyway).
In General, use a credit card like you use cash.
It's better than using a debit card where money comes directly out of your account, as long as you pay it off immediately.
This is because if someone tries to scam you, you can call the bank and do a chargeback on those bastards.
Also... 30% total? I thought it worked like... You know, lemme put this in perspective
The credit limit is 100 bucks
You use 30, nice, at a certain time of month, the bank tell you to pay off that 30 buck, then it resets to 100, rinse and repeat, stonks credit score
It doesn't work like that?