Keep your head up. You do not control the ebb and flow of the universe. You are just trying your best. And trying your best does not mean spending every waking moment planning for the future. Trying your best does not mean acing every test, interview, interpersonal issue, and obstacle that is thrown your way. Trying your best does not mean you get things done or you get further than your peers. Trying your best does not mean you do not make mistakes.
You seem to be under the misconception that you have to be somewhere. That you should've been somewhere by now, or yesterday, or a year ago. That someone of your caliber, of your potential, with the opportunities and resources you've been given, should have something to your name, something to show for all the blessings you've received. Something to show other people that you used your time well and you stewarded your skills appropriately, and something to prove to yourself that you deserve a pat on the back.
You also seem to believe that everything will just line up for you. That every failure, every mistake you make has to be your fault, because you have what it takes to do anything. You think you should be immune to failure, and any evidence in favor of the opposite just means that you're doing something wrong. You get frustrated when things don't come easily to you, as if you were supposed to waltz your way to all your goals and ambitions.
Don't get me wrong, you are capable. You learn quickly and you have the drive and patience to keep on trying new things. That's a lot more than most people can ask for. But you mess up too. You excel in certain areas, but are absolutely helpless in others. You have to put in just as much work to get to where you want to go as everyone else. Your gifts are nothing special, just as everyone has their own areas of expertise. So please stop getting discouraged when you fall flat on your face, when you tried your hardest and just didn't make the cut. It doesn't mean you're bad, or worse, or incapable, or any of those things. It just means you messed up, or maybe you didn't have what it took at the time. It has nothing to do with your over-inflated expectation of your abilities.
So let bad things happen. Let yourself fail; let yourself waste time. Let yourself enjoy life. You are not depriving yourself of a better future if you miss a day of opportunity to hang out with your friends. There is no better timeline where everything magically lines up and your life is just so much better than it is here. It's just you, and it's up to you how to live. You can try to an extent, but you can't make everything go the way you want to. It just doesn't work like that.
Let yourself be bad at things. It's the only way to get good. And even if you never do, let yourself enjoy trying to improve.
Take it easy. Stop thinking about this and that, what would happen if this or that, and the rest of the useless questions. Just try your best and see what comes next. If you already knew that you'd win every single one of your battles, what's even the point? The whole point is that you are comfortable in the everyday, in the present, without knowing what's going to happen the next day. Let yourself be let down, and let yourself be pleasantly surprised.
Do things for the sake of doing things, not for the consequences they bring. If you do desire the consequences, do not expect them. You will burn out and lose the passion that once made you so motivated. You have to do things without thinking about the future. Just do and don't think.
Even if you were incapable of doing any of things you can today, you deserve to enjoy life. You deserve to listen to good music and have fun with friends. It's not even that you deserve it, to be honest. It's just not that big of a deal. Let people live, and let yourself live as well. There is nothing better to do on this earth.
Take care of yourself. You can't do anything if your body and health are weak and fragile.
Don't be afraid to waste time. This goes both ways: don't stress over losing a day of work, but also don't get anxious about trying to get work done and failing. Just do stuff and don't think. The change and the consequences will slowly build up, but you will rarely notice it.
Continue to learn and create. It is the best thing for you to do.