One of the underappreciated blessings of post-adolescent existence is the relief that, barring some great tragedy, you never have to feel so much again -- especially the pointless self-hatred your teenage years seem expressly designed to create. In that sense, 16-year-old Rae (Sharon Rooney) -- the smart, funny, overweight, depressed, and horny-as-hell heroine of the instantly classic teen drama My Mad Fat Diary, which ran from 2013 to 2015 on the U.K.'s E4 network -- has a lot to look forward to. But for now, she’s stuck in a small town where she’s convinced no cool people live, and which is a psychological bear trap that hobbles her with the belief that she’s too ugly to be shagged or loved or even have friends.

Rae is mistaken on all counts, and much of the pleasure of this ’90s-set British import derives from its protagonist being shown the error of her ways, time and time again. Available for the first time in the U.S. via Hulu as of April 9, My Mad Fat Diary’s three seasons stand alongside Freaks and Geeks and Friday Night Lights as one of the best modern TV shows about high school. Based on author Rae Earl’s memoir of the same name, its emotional might comes from its marvelously detailed portrait of dealing with obesity and mental illness, as well as its fresh approaches to the messiness of female sexuality and best friendship. (It’s enough of a U.K. cult classic that MTV commissioned an American remake back in 2014.)

Melissa McCarthy just kicked Batman and Superman’s asses at the box office with The Boss, but she’s pretty much the only lead actress who’s allowed to be fab while fat. (With Super Fun Night forgotten, when’s Rebel Wilson getting her own starring vehicle again?) Rae eventually reaches the McCarthy glow after many a setback, but her complicated humanity -- still so frustratingly rare to see in heavier female characters -- first demands that we see her pain. In the pilot, she returns home from a four-month stay in a psychiatric institution following a suicide attempt. Her pathological fear of looking at herself in the mirror is bolstered by everyday humiliations: street harassment; her uncompromised virginity; and an invitation to a pool party, where her new friends might see her stomach bulge -- or, even worse, see the horde of scars she’s cut into her thighs over the years. Shame multiplies: Rae has to hide not only her body, but also the evidence of her hatred of her body, and, later, the fact that she had to get help to cope with that self-loathing.

Rae’s secrets and anxieties are entirely normal for her age, but, as one of her doctors points out, her instincts in how to deal with them are not. Unsurprisingly, it’s her body that she punishes for its seeming transgressions -- by, say, scalding herself in the shower or scraping her knuckles against a brick wall. She starves herself at school for fear that the sight of her eating will invite further taunting: If she snacks on something healthy, people will assume she’s pretending to have good eating habits; if she noshes on something junky, they’ll blame her for gaining weight. There’s no winning for Rae, and she struggles throughout, with the aid of her kindly psychiatrist (Ian Hart), to see some semblance of victory for herself in the future. In perhaps the show’s most heartbreaking moment, she breaks up with Finn (Nico Mirallegro), her caring dreamboat of a boyfriend, because she’s brainwashed into thinking they simply don’t look right being together: “It’s embarrassing to be next to him. I’m embarrassed for him.”

But for all her revulsion at her fat, the slightly boy-crazy Rae remains delightfully committed to the possibility of sexual pleasure. Salivating over a crush in the first season, she confidently declares, “I’d shag him until there was nothing left.” When she gets to Finn’s place for what she’s expecting to be The Night, she can’t help winking to herself, “Even his house was a bit sexy.” Before that, Rae teaches herself how to masturbate and scribbles pencil doodles of boobs and cocks all over the screen. A story line about periods and abortion in the third episode -- an early peak for the show -- suggests the additional burdens female bodies come with, but the show is often buoyed by Rae’s overwhelming excitement. This is, after all, a girl who explodes into teal powder and silver penis confetti when her boyfriend manages to make her happy. (Again, it’s hard to overstate how unusual this depiction of a plus-size female with a healthy libido is.)

In a rather ambitious episode late in the sophomore season, we discover the unreliability of Rae’s narration throughout the series. There’s often a big difference between how the teen presents herself to us and how she actually behaves in her interactions with her flighty single mom (Claire Rushbrook), whom Rae initially introduces to us as “Mother,” adding a beat later, “(fucker).”

But Rae’s self-conception -- and the show’s framing device -- gets a brutal shakeup when we see the extent to which our protagonist’s view of herself (as fragile and unwell) enables a deep self-centeredness that endangers her relationships, especially with her childhood BFF, Chloe (Jodie Comer). Rae’s interactions with her mom and Chloe are when she’s at her most flawed, and therefore the most human. Rae can only see in Chloe what she doesn’t have: her thinness, her popularity, her affluence, and her conventional attractiveness. But that leaves Rae blind not only to her own assets, but also to Chloe’s trials, which include self-esteem issues so crippling they leave her vulnerable to multiple predators. Rae leans on Chloe so often, as when she narrowly escapes a sexual assault, that she can’t see that her friend’s eyes are glassy and unfocused, all but screaming for help too.

Their relationship is one of the strongest elements in a show already filled with extraordinary and sensitive portrayals, depicting as it does a pair of girls who probably wouldn’t be friends if they met now, but who feel an intense loyalty to each other because of their lifelong history together. It’s a familiar coming-of-age trope, but no less affecting for it. Rae and Chloe often have to remind themselves to think back to their pigtails days -- and swallow a drop of bilious resentment -- to stay friends sometimes. But until they go off to college, at least, they know that putting in that effort will pay off.

After a pretty flawless debut year, the slightly longer second and rather short third seasons have a few more melodramatic turns than even Rae’s life warrants. But most of My Mad Fat Diary is as real as real gets, from the actors who look as if they could be kids off the street and the period-appropriate ’90s soundtrack to the two blonde toothpick bangs making an upside-down V from the middle of a mean girl’s forehead. Rae’s a creep, and she’s a weirdo. She’s also bloody wonderful, and watching her slowly realize that through her journal entries is probably the best thing you could do for the wounded teen inside you.