<human>: Condense the text into a few key points

I received my credit report from Transunion and found out my student loans were delinquent from July 2011 to January 2012. I began personally paying my student loans in February 2012, my dad was handling the loan payments prior so i could focus on school but told me quite a bit late to begin handling them myself. When i began paying, it was about $26000 subsidized (5.3%,) $3000 unsub (6.8 %.)

I fully paid off the unsub loan a few months ago, and have the subsidized loan down to $21000. I am currently looking to move and called my credit card to have my credit line increased (to buy furniture, pay rent electronically= easy reward points) 

The increase was declined even though I'm self employed making about $140,000 annually now that I'm done with school. I need help understanding what I should do now. I plan on paying off the student loan in full Friday, will that fix the issue? I called Federal Student Loans earlier and they told me I need to write a letter explaining my situation. I will do it but it seems like a slow process. 

I am baffled the credit card company can see the past delinquency but not see I am no longer delinquent. All my credit cards and bills are always paid in full monthly. I'm not as concerned about the credit line increase, its the apartment applications that is worrying me because I assume they will check my credit. I can provide any needed information.
<bot>: past student loans delinquent because of dad. been paying well over minimum for 6 months now. delinquency still hurts my credit regardless of making 6 figure income. What should I do?