I (22F) have a best friend, "K", who recently went through a painful breakup. Over the past few weeks, she has been extremely upset and leaning on me for emotional support. I care about K deeply, and I've tried my best to be there for her - talking for hours, comforting her when she cries, and even letting her crash at my place a couple of nights when she couldn't bear to be alone. It's been tough on her, and I understand that. However, it's also been draining for me because her calls and texts often come very late at night and it's affecting my sleep and daily life.

Last week, I had an important presentation at work early the next morning. I told K earlier that evening that I needed to get some serious sleep and might be not available if it got too late. She said she understood. Despite this, around 2 AM, my phone started buzzing - K was calling, again. I woke up and saw her name on the screen. I hesitated. I had already spent a good part of the evening on the phone with her, helping her calm down from an anxiety attack about her ex. I was exhausted and desperately needed rest for my presentation. So, after a moment of guilt, I decided not to answer. I put my phone on silent and went back to sleep, figuring I'd explain and check on her first thing in the morning.

When I woke up, I found a string of angry texts from K. She'd had a panic attack overnight and felt completely alone when I didn't pick up. In her message, she accused me of abandoning her and being a "selfish, terrible friend". She wrote that she "needed me more than ever and I couldn't be bothered to answer". Reading that broke my heart. I felt awful knowing she had suffered alone. I immediately called and apologized, trying to explain that I wasn't ignoring her out of malice - I just genuinely couldn't function without sleep that night. I reminded her I had that big presentation and had warned I might be unavailable. K responded coldly that it must be nice that I can choose to check out, whereas she can't escape her misery. She hung up on me after saying I let her down when it mattered.

Now K isn't really talking to me. I've heard from a mutual friend that she's still saying I betrayed her trust. On one hand, I feel incredibly guilty - my friend was in crisis and I wasn't there when she reached out. I keep wondering if I should've just sacrificed a night of sleep to support her; my presentation seems trivial compared to her mental health. On the other hand, I've been emotionally exhausted and I worry that if I don't set some limits, I'll burn out completely. I honestly thought one night of not picking up was reasonable since I had been there for her so many times. I never wanted to hurt her, I just needed one night for myself.

I'm feeling really torn and like I might be a horrible friend. I wonder if I handled this poorly and if I should have found another way. So, Reddit, am I the asshole for not answering her late-night call during her breakup?