You work as an instructor and build you hours at your GA Airport until you reach the minimums for the Airlines and then you apply. Rejected? Apply again, and again, and network and network at the airport as much as you can.
The sooner you pay off your loans the sooner you can follow a plan.
Your life ends when you die, not in your late 30s...
Sorry you aren't going to get hired at an airline in your early 50s with just instructional time. Following your plan would work well if the end goal was an instructor and/or GA charter, but forget airlines ain't going to happen.