Today I joined more than 500,000 women and allies who believed that women's rights are human rights.

Organized in cooperation with nearly 200 progressive groups, The Women's March on Washington represented everything from LGBT equality to voting rights, racial justice, access to abortion, gun safety, the living wage, healthcare, immigration reform, and the environment.

And current estimates put the total number of protesters in sister marches around the world at 2.5 million.

The crowd marching through the streets of the capital today was as diverse as it was massive: I saw old women being pushed in wheelchairs, energetic teens leading chants of "We want a leader, not a creepy tweeter," and fellow LGBT activists sporting rainbow capes, glitter, and unicorn horns.

I also saw an impressive number of parents toting their kids, some in strollers, strapped to their chests, or hoisted on top of their shoulders. And of course, I saw hundreds of thousands of pink pussy hats.

In the weeks leading up to today, I hoped that when I arrived, I'd feel hopeful—or at least relieved. For me, as for so many of us, the future's felt uncertain ever since Trump was elected.

I knew I'd get to march alongside two of my oldest friends—pictured below, I'm in the middle—women I co-founded my college's first feminist club with. Who I regularly marched against the Iraq War with in the early 2000s.

I was desperate to believe that marching alongside them, and hundreds of thousands of others, would be a salve to the anxiety that's plagued me since November.

I did feel some of that: My friends and I live in different cities, so our reunions are always happy. But I also felt a profound sadness. Part of that was the result of the build-up to the march.

When I arrived in D.C. Friday night after a long, stressful day of travel, the prevailing vibe was dystopian: The Metro was full of protesters in pussy hats and protest t-shirts, but just as full of people wearing "Make America Great Again" hats. Others were decked out in ballgowns and tuxedos en route to inaugural balls.

All of us were packed into the same tiny space together, but everyone seemed to be taking care to talk quietly among themselves—no eye contact with strangers. In the streets, helicopters circled overhead and lingering protests from the inauguration itself were still dying down. I walked past a trash can on fire. Police in riot gear looked on calmly while seven or eight teenagers crouched around it, filming it with their phones as it burned.

This morning at the pre-march rally, the feeling in the streets was much more exuberant, despite the overcast, damp weather. But there was also a tangible sense of anger, and of disappointment and fear.

Early in the day, we'd come across a group of counter-protesters carrying signs like, "The wages of sin is death" and "Warning: Drunks, homosexuals, abortionists, liars, fornicators, thieves, atheists, witches, idolaters, HELL AWAITS YOU."

There weren't many, but they had bullhorns. And they reminded us all of how much hatred was amassed against us. At one point, one of my friends looked at me with tears in her eyes.

"I wish we didn't have to do this," she said, her face filling with angry tears. It was a sentiment I heard echoed throughout the day.

"I'm really, really angry about the system that allowed Donald Trump to be elected," Rebecca Laung, a queer 26-year-old from Boston told me. She wore bright red lipstick and a "Black Lives Matter" pin, and had glitter all over her cheeks.

"I wanted to be around other angry people. It's empowering in some ways, but it's also a little overwhelming right now."

Rebecca's partner, 24-year-old Gaby Waldman-Fried, added, "I'm glad to see so many people here who want to be heard, but I really hope this is just a starting point for people doing the real work that needs to be done—which isn't just attending this march."

I asked an older woman in an "LGBT Task Force" t-shirt what being at the march made her feel.

"Terror," she said. "This whole thing is terrifying." That resonated more than I wanted it to.

There were, of course, beautiful, moving, hilarious moments today, too. A brass bands played "Uptown Funk" and people danced to it. Celebrities spoke and performed—Madonna, Scarlett Johansson, Janelle Monáe, Alicia Keys.

The protest signs were funny as hell.

And despite all the unavoidable jostling in crowds of this magnitude, people were overwhelmingly gracious: They shared snacks from clear tote bags. They let children cut to the front of long Porta-Potty lines. (Elderly people, too.)

People hugged when they ran into old friends (and lovers). They sang emotional renditions of "This Land is Your Land" and "We Shall Overcome," along with some newer protest jams, like Chance the Rapper's "Blessings."

Those moments of hope and relief I'd wanted were there. But they didn't temper the ongoing anxiety I carried with me all day. Which, in the end, is a good thing.

Because as cathartic as today was, it wasn't the end. Far from it. Solidarity won't be enough to get us through the next four years and beyond. This is just the beginning of a lot of hard work—of fighting discrimination, legislation, and the rolling back of everything we've fought so hard to gain.

At the end of the day, we passed a group of gray-haired women leaving the march. One of my friends said to me, "I hope we all go home and do the work we need to do to make sure, by the time we're their age, we don't have to do this anymore."

I hope so, too.