(I'm an old(ish). Thanks for considering this advice, given earnestly and with good intention, from experience.)
Assuming the nature of your work isn't the source of the sadness? The gratitude you mentioned... Find ways to blow that up! Reflect on whether a past version of yourself would be proud of where you are now. The peace of boredom is a blessing. Seriously! A large amount of time spent as an adult is simply existing day-to-day. It gets repetitive, "there's nothing new under the sun."
But also, stay as healthy as possible so you can do things outside of work. Make sure you are getting enough sleep, eating well. Don't smoke or vape anything. Maybe when the rhythm of your career settles in you will be able fully build out your whole life and work will only be a little part of it. The transition from school to career is temporary, trust that you'll get the balance right soon enough. IDK... I wouldn't know about long term careers, π I have done a bunch of different stuff since I finished with school, none of it even close to what I went for. If I got bored or outgrew it or it got toxic, I moved on. No one *wants* to labor, right? Capitalism π€¬ sucks. But we *do* want to contribute to society, to our communities. Many types of work do that even under capitalism. So. Whatever you do, be grateful that you are contributing, but realize it doesn't define you, and learn how to be grateful for things that you might otherwise not be, like boredom.
Gratitude is always the answer, especially to sadness; and comparison is a thief of joy.