So, about a year ago, I finally completed the final achievement, becoming friendly with the Red Devils, and ever since then, I've just been flying around doing whatever the <bleep> I liked to do. Which means, I took on only the big million+ credit jobs, selling whatever the hell falls in my cargo hold. Until today, that is.

Because today, my credits counter turn around on me. I passed the 2.14 bln credits, and now it's in negative mode.
I just wanna keep doing flying fun missions, but I cannot buy <poo poo word> anymore. What is a Bobo to do now?

Ask the developer very kindly for a fix? If they do fix it, I suspect that all they will do is put a cap on your money so you cannot earn more; better that than going into minus.