Did you always think, "I've got some great things ahead of me", and now you ARE grown up and this IS the future and you're worried about what you have to show for it?
Maybe you want to have great friendships and do great things and all these seem to require so much energy and attention and so many steps to not mess up. If that's the case, I'd say try dialing back, focus on enjoying the journey and less on the result, because really there is no guarantee that the results will be awesome.
You say people respect you for many things but that you have a "terrible" problem with discipline and focus, something I suspect most everyone has. Maybe you're just giving yourself too much pressure and need to take it easy for a few months? Since you're still in school, have a chat with a psychological counselor on campus. To me it sounds like you might be temporarily stressed out or burned out from the efforts of your previous startup.
Peace.