Get rid of all but one or two credit cards. You don’t need retail store cards or gas cards, which typically charge the highest interest rates.
If you have a balance on more than one credit card, transfer the balances to the one with the a lowest interest rate, or simply pay the most you can afford each month on the card with the highest interest rate.
You are not obligated to accept the credit limit assigned to you. If the temptation to spend is too great, call your card issuer and ask customer service to have your limit lowered.
Switch from credit cards which carry an annual fee. There’s no reason to pay extra for the honour of paying high interest charges.