Hoo, now we're getting into the nitty gritty.
Degree requirements vary from airline to airline. I don't think you need a Bachelor's Degree to get hired on with many of the regionals, but I'm uncomfortable with giving you blanket advice on this issue. You're probably closer than you think to an Associate's Degree based on your work experience alone, and that certainly wouldn't hurt.
There is no specific bachelor's degree you need to attain. I've flown with engineers, historians, economists, you name it. You may wish to consider pursuing something that will allow you to build on your practical experience, like business or structural engineering. That said, there are many respected universities that offer bachelor's degrees in aviation-related fields. I advise only that you consider avoiding really fluffy subjects, like tissue paper sculpture or something (Cue someone interjecting: "Hey, I majored in tissue paper sculpture and I'm now a FedEx captain!").
Regarding timelines, there are too many variable for me to assess to give you a good timeline: do you live in the wilderness north of Juneau somewhere, or are you in a major metropolitan area? How many hours per week do you need to work to keep food on the table and a roof over your family's heads?
I am, however, ready to make some firm recommendations:
1. Run a Google search for flight schools in your area. Call some of the schools and make some appointments to speak with their people and get some real numbers attached to the pursuit of your goals.
2. Run another Google search, this time for aviation programs at colleges and universities near you. Make some calls. Get some hard info.
3. Assuming you live within driving distance of a community college, make an appointment with that college's admissions office to find out about AA or AS degree programs, possible aviation-related programs, and college credits the school may award you for your work experience to date. Assuming you're a fully licensed welder, you may already be halfway to your Bachelor's Degree.
4. This is the fun one: buy a copy of Microsoft Flight Simulator on Steam. Buy a good joystick (like this one:
https://www.amazon.com/Thrustmaster-.../dp/B001CXYMFS). Do all the lessons and missions and go through the simulator's virtual flight school. A home simulation won't make you a real pilot, but the skills you build will knock a measurable amount of time off of your time-to-train.
If you have any more questions, feel free to ask. Please keep in mind, however, that I'm just a stranger offering free advice on the internet. At the end of the day, you're going to have to do your own due diligence.