Ben Platt has played his share of lovable weirdos — notably magic-nerd Benji in the “Pitch Perfect” film franchise, and a replacement Elder Cunningham on stage in “The Book of Mormon” — but in his latest role he’s got to be way more than weird. He’s got to be the poster child for teen angst.

Luckily, Platt has turned nervous wreckage into an art form, as he fidgets, stammers, slouches and nail-bites his way across the stage — all the while singing, mind you — in the title role of “Dear Evan Hansen,” a new, critically hailed Broadway musical at The Music Box theater. Directed by Michael Greif (“Next to Normal”), with a book by Steven Levenson and music and lyrics by Benj Pasek and Justin Paul, the story follows Evan, an anxious, bullied teen, and his classmates in the aftermath of a teen suicide. Tough, tantalizing material, and Platt’s strong performance will likely earn him major Tony buzz this spring.

Platt, 23, grew up in Los Angeles, the son of a producer. And while he claims to be somewhat laid back, he speaks at Evan’s lightning-speed clip. He chatted (fast) with Newsday contributor Joseph V. Amodio.

You must be exhausted.

A little bit. [He chuckles.]

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Your character is sweet, funny, but also frenetic — talking fast, existing at this fever pitch. Is it a challenge, or do you run at a similar tempo?

I really don’t. I’m more laid back and less manic than Evan. It’s definitely the most heavy-breathing part of my day. [He laughs.]

Evan’s tics and quirky mannerisms must be tough to turn off. Do you find yourself in the aisle at Rite Aid doing something that you realize is more Evan than Ben?

Definitely. My posture isn’t great these days. Sometimes the fidgeting and nail-biting linger into real life. I’ll be with close friends or family — people I feel at ease with — and yet I’ll still be fidgety, or sitting in a ball, and they’ll ask, “What’s making you so nervous?” I’m like, “It’s not you, it’s not you.” It’s just . . . I just can’t shake it sometimes.

There are moments where you have to sing angrily. Or through tears. How tough was that to master?

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That was definitely the biggest challenge. As far as the anger goes, the trick is to hold the tension in an emotional place and not your neck, so you’re not just . . . choking notes out. The tears . . . that was more difficult, because I’ve never had to cry and sing at the same time. But those moments have become some of the more freeing parts of the show for me. When you cry, you expel a lot of mucus, from your sinuses and nose — sorry for being graphic. And that actually opens up a lot of space to resonate and make sound. So now that it’s second nature to me, it’s great.

The discussion of social media in the show — our addiction to it — is also intriguing. Has doing the show changed how you think about social media, or what you post online?

A little bit. It’s . . . put things in perspective. I’m cautious not to look for validation within social media, or judge my worth based on the responses I get. It’s allowed me to be detached more than I might have been otherwise. But it also makes people feel connected. Our fans have been wonderful — they want to interact, and learn about the process, and getting to share that with them directly is really valuable. So I’ve come to appreciate the good things about social media and try to be wary of the pitfalls.

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You were, I gather, a lot less fragile in high school than Evan. How big of a theater nerd were you?

Huge! That was all I cared about, all I cared to talk about. I found a solid group of friends who were also theater nerds — into improv and musicals. They’re still my closest friends. So I was far more fortunate than Evan as far as finding people who wanted to see me and understand me, and who I wanted to understand, as well.

So how do you relax? Do you get to just chill and disconnect from Evan for a bit?

I try to surround myself with friends who are supportive but who continue to treat me as Ben — not as this person playing Evan — and bring me back to myself, if that makes sense.

Sure.

I also watch TV. Very light television. “Parks & Recreation” is my go-to. Some nights, when the weight of the show lingers a bit, it’s a way to take a breath and come back down. And then, [he chuckles], and then there’s sleeping.

I hear ya.

I love to sleep.