Applied at investment bank for Unknown

Today was a tough day at the investment bank where I work. My coworker, who has been with me for about six years, just hard quit. We both handle a significant portion of the workload, and it has been overwhelming lately. Last week, he expressed his frustrations about the heavy demands, and then on Monday, he just disappeared. I can't say I blame him, but now I'm left to pick up the pieces. I've been feeling the pressure for a while now, with tightness in my chest for the past two weeks, and yesterday it hit a peak. I realized I couldn't keep up with both my tasks and his, so I decided to clock out at 5 PM as a form of rebellion against the unrealistic expectations. Now, I'm at a crossroads. I need to decide whether to hard quit, give my two weeks' notice, or start looking for another job—though I'm so burnt out that the thought of interviewing feels impossible. I have enough savings to last me a year, but the idea of faking enthusiasm in an interview just doesn't sit right with me right now.