If you want to eventually fly for a major airline, a college degree is required. The quickest way to that goal is this.
Get all of your ratings through CFII and AMEL. Start instructing and then enroll in college while you're instructing. You'll be building time while you're in college and if it takes you 4 or so years to graduate, you should have enough flight time by then to get on with a regional airline.
Fly for a regional for a few years, and you'll be qualified to work for a major.
Assuming at least a year or more to get all of your ratings, then 4 years of college, then another 4 or 5 at a regional, you're realistically looking at about at least 10 years from start until possibly hired by a major.
There is no quick way to do it or short cuts. You have to have a degree, and you have to have the flight time. Just like there's no way to become a doctor in a couple of years, there's no way to become an airline pilot in a couple of years. An incompetent pilot can kill a lot more people than a doctor.