You are feeling bad because you are feeling sorry for yourself, thinking about everything you wish you had but don't, you think you alone have been left behind by life, and everyone else is moving on. But actually, everyone is in the same boat. We are all suffering with our unfulfilled dreamed, anxieties and struggles. Life will never magically give us what we want, and even people who have everything will find something to fret over.
You need to find satisfaction in the things you are capable of doing now. You have to be more confident that you are doing okay in life. If there are things you wish you had, that's great, those are called dreams and aspirations, work towards them one small step at a time, don't despair that you don't have it right now. And by the way you will definitely fail lole, we all slip and stumble through life, but the biggest bravest thing that a person can do is pick themselves up again and keep going, keep trying, keep step step stepping forward. You only get one life, anything at all you gain from it is a net positive.