Big plans. That's good. But maybe a bit too much emphasis on getting there by 21, but what do I know. I do know that there are kids getting to the regionals fast with a 4-year degree. But because they wanted to get there fast and be sure that they would get right in, they (or their parents) dropped bigtime coin at places like Embry. So now they are making very average money and are saddled with ridiculous debt. It's a little sad actually. I almost feel that these schools and flight academies are taking advantage of the pilot shortage hype and pushing the "you have to do it now and do it fast or you'll miss out" bit.
If you or your parents have money burning a hole in your pocket, then pick a university and get the bachelor's as quick as possible. Otherwise how about going to a community college that has an aviation program and get two years in that way, then finish up at a university. You'll save a boatload of cash and spend only marginally more time.
Either way, you should get the bachelors.
One other thing to think about. I wonder how far along you are in flight training? Do you have your private? How much flying and what types of other flying have you done other than primary training? Did you grow up around aviation? The reason for that question is that if flying isn't the be-all and end-all for you (other than in your imagination what flying all the time might be like), you may end up being one miserable dude. That's just another good reason to go the community college aviation program route - it gives you another 2 years to see if you actually want it to be just a job or not.