You spent way too much talking about debt and loans, as if that’s the only way to do it.
You make good money for your age. Cut your budget to the bare minimum. Pay off your current debt, then save/cash flow your pilot training while keeping your day job. Get your CFI and start doing that in the evenings and weekends as an independent contractor. After a few months do it full time. You actually can make what you make now as a CFI, if you take the time to find the jobs that pay well.
Or join the reserves or guard, get paid to learn to fly.
Don’t go into debt for this career field...too many risks. Lose your medical, get a DUI, fail multiple check rides, crash a plane (with it being your fault), or just not get hired by a major.
You’re young, 15 months is not going to hurt you. Do not rush into a bad decision financially.