<prompt> Human: I have always had bad financial habits. When I was younger I just did not realize the importance and as I got older I just got into the habit of thinking screw it, Im never going to have decent credit. I then just avoided the issue for years. Buying cars at high interest rates, rent to own furniture, payday loans, fingerhut, an hsbc credit card with 250.00 limit that I maxed out within two days of receiving it andnever paid, overdrawing on checking account purposely just because I wanted money to buy something. Which often times was things like gas, groceries, car payment etc. It was just an endless cycle. I even filed bankruptcy at one point and my debts werent even that high. Less than 15 thousand at the time..so, about 2 years ago I started really paying attention to finances. I quit overdrawing on checking account, I quit eating out so much, I resisted the urge to go to the store and buy things I didnt really need. Paid off my car. Started putting money into 401k at work. Moved myself and my child out of my ghetto , roach infested apartments into something nicer and things were going well. I finally decided to face the music and pull my credit report. I had a score of 540 and around 7 negative things from the credit card to medical bills. I was tired of bad credit. I researched and saw via an online message board that a good way to repair bad credit was to open a credit line, use it and pay the bill off every month but carry over a 5 to 10 dollar balance. I applied for an amazon card. Got denied. A couple months later applied for a capitol one card and surprisingly got approved for 300.00 limit. I used the card for gas and a couple things that auto pay like netflix and cell phone bill. I paid balance every month and carried over small amount 5 to 10 dollars. I was told that after 5 months of on time payments and as long as I used the card at least once a month I would get an automatic credit line increase and I expected it to maybe go up to around 750... it went up to 3 thousand... Im honestly a bit scared because I feel almost like an addict who has been away from drugs for years and then suddenly someone gives you a bag of drugs and you dont want to start using again because youve been doing so well. Anyways do I just keep doing what Im doing and using the card like I have been or do something different since limit was increased? I just want to make the right moves so I dont screw up again and also I do want to keep rebuilding a positive credit image. Thanks for reading this if you did.  <response>: Keep doing what youre doing. Do not use the card for anything other than a planned expense. Pay your bill in full every month.PS: you do not need to pay a dime in interest for a good credit score. 