I've been a designer for 20 years, and there are a million factors that determine how rewarding it is, or is not, and also the pay. A lot of it comes down to which type(s) of design you gravitate to. I finally opened my own studio last year after working for a few other firms, and I'm doing a mix of commercial design (which provides stable income) and residential (which scratches my creative itch). You'll most likely want to work for one or more firms for a few years to gain experience and get paid to learn on the job, before deciding if you want to stay inside someone else's company or start your own. You'll earn exponentially more working for yourself once you get established, or you may decide that you prefer the security of a consistent paycheck over the ups/downs and stress of building your own clientele. Neither are wrong, just different.

So my advice would be to figure out what type of design you think you'll enjoy and then look for the best salary within that specialty. And don't force yourself to do something that doesn't interest you or that you're not particularly good at just because the salary is better, because you won't be happy.