Are you trying to play with the loan (hard difficulty) specifically?
Because if not, just focus on the story. You shouldn't have to pay the loan more than the first two times, unless you're taking your time with story. Focus on the "hustle" for a bit, especially reputation with the guilds through jobs, and the loan will become a non issue.
Spoiler : something will freeze the loan payments until resolved.
Now if you know this already and are playing with the extra difficulty or option for the loan to continue, that's like, optional challenge so it shouldn''t need to change.
Make sure Fast Loan Payment is checked, too. 