Running a startup is hard. Soul crushingly hard. I suspect if you haven't done it before, you can't understand it, but I'll try to explain it with an analogy:
Imagine you decide to row across the Atlantic alone. You don't get a GPS, you don't get a map, you don't even get a compass, all you can do is navigate by the stars. Oh yeah, you do get a one way radio you can't turn off.
At first, as you leave your home filled with confidence. You know you're a strong rower, you think you know where you're going, and you you feel great!
But then it gets dark and cloudy, you can't see the stars, you have no idea where you are, you have no idea if you're going in a circle or heading back to where yous started, and you're tired, rowing is hard work. You become filled with fear and doubt. Even if you wanted to go back to a place you thought was safe, you don't know how to get back. And did I mention rowing is hard work, and you've been rowing a long time, and you're tired, very very tired.
While you are it in your boat alone, in the dark, anxious, exhausted and demoralized, you still have the radio, the radio you can't turn off. The radio is a stream of people give advice like: "You're going the wrong way", "Turn Back", "Go Left, "Go Right", "Turn around", "You're crazy to think this will work", "This is dumb", "you're doing it wrong".
But sometimes , the clouds lift, and you see the stars, and you realize you are making progress, you realize you are a stronger rower then you where when you left shore, and you fill with hope. You recharge your mental batteries you remember why are on this journey, and most of all you remember you can actually make it!