Almost two-thirds of millennials say they're living paycheck to paycheck and only 38% feel financially stable, according to a new survey from Charles Schwab. Millennials, more than any other generation surveyed by Schwab, feel the most insecure when it comes to their finances. That's according to roughly 380 millennials (ages 23 to 38) surveyed for Schwab's 2019 Modern Wealth report.

Yet millennials also say they spend an average of $478 a month on "nonessential" purchases, such as dining out, entertainment, luxury items and vacations. That's less than the $587 Gen Xers report spending, but more than the $359 spent by baby boomers. "It may seem odd that when we look at statistics that say so many millennials are living paycheck to paycheck, but on the other hand, they're overspending," says Farnoosh Torabi, personal finance author and host of the "So Money" podcast. Schwab partners with Torabi's Stacks House, a pop-up experience that promotes financial independence for women. But while it may seem counterintuitive, it's the reality many millennials face, she says. "When your financial life is in disarray, chances are, you will overspend," she tells CNBC Make It. "Emotions around money lead us to make irrational choices."

It's not just a spending problem

It may be easy to criticize millennials for simply spending too much, but other issues are also at play, Terri Kallsen, Schwab's executive vice president of investor services, tells CNBC Make It. "Spending is not the enemy that we might think that it is," she says. As a generation, millennials also are facing systemic financial issues that can feel overwhelming. They generally carry more debt than previous generations did at their age, for example. One major reason for that is student loans. The number of households with student loan debt doubled from 1998 to 2016, Pew Research Center found. The median amount of loan debt millennials carried was $19,000, significantly higher than Gen Xers' balance of $12,800 at the same age. Student loans are not the only kind of debt millennials hold. About 40% of millennials (defined here as those 20 to 35 years old) have credit card debt, according to a recent survey by LightStream, the online lending division of SunTrust Bank. Millennials ages 25 to 34 had an average of $36,000 in debt last year, excluding home mortgages, according to Northwestern Mutual's 2018 Planning & Progress Study. Rising home costs and the fact that salaries just don't go as far as they once did to cover the necessities also adds to the pressure. "When you're saddled with student loan debt, when you have credit card debt, when you don't have a lot of financial literacy, that can lead you to making unhealthy decisions with your money, including overspending," Torabi says.

It's about finding 'balance'