As Simon Sinek put it: Start with WHY. Find your own “Why”, for yourself: Why exactly you do what you do in life? Is grad school the right place for you to be? If so, why? If you think it isn’t, why not? Why did you go to grad school in the first place? What was that original piece of motivation that might have gotten lost along the way? Locate it and think about it.
Don’t be a loner. Humans are social animals, so be human and have your circle of like-minded people. The World of Academia is so much more enjoyable with friends & colleagues. Don’t underestimate the efficiency a “team” can provide you with. A group of people sticking together and helping each other when it gets tough (as it does, sometimes) will always be more powerful than a single individual pissing against the wind.
It’s a long walk to graduation – but it’s worth it. So don’t listen to the naysayers, and just keep going. You can do it.