Difference is I'm 5 years your senior, and not that those 5 years matter all that much - but what I've come to learn is that what you're feeling is part of growing up. It's part of becoming an adult, and realizing that life just... isn't fun. Like, in itself. What I've found is to take joy in the little things, and try to improve what I can control. Large things like money, work, love - that's hard to control. What you do in everyday life, how you handle little tasks and little conversations, those are more controllable and much more defining to you, and therefore much more defining to life - and who you are. Work becomes routine, even if the tasks at work itself aren't. Paychecks are routine, time is routine, even holidays can become routine. Even something grand you've planned, a party or something, can end up quite boring - but really, it's... it's okay.
I guess what I'm saying is as you get older, you accept the boredom and the routines, and that's when you get cooky and starts having fun with the small stuff. Like, your relations to other people. I was never really fond of your random person, now I embrace socializing much more. Even the guy at the grocery store. I call my mother more often. You know - small stuff.
And also, you're perfectly allowed to feel shitty. (And have as much chocolate as you wish when you do.)
Also, I think the "shrug" thing at things you do at work and the likes are connected to self esteem. As you get older your feeling of self grows, and also your self esteem. One day when people say "wow, that's awesome what you did!" you'll be able to really feel happy and enjoy the praise and feel "yeah - I know!" instead of having the "shrug" feeling. Don't worry
