Introspection and learning from past mistakes are important for honing one’s skills and finding a better path. However, being overly harsh to yourself all the time is a recipe for depression. First of all, you are in the business of learning, not showing what you already have. You probably have no idea how much you can change and improve. Each individual’s different, but anyone can learn and improve themselves and their outlook. You certainly can too.
Remember this one crucial thing: You will be fine. Have a faith in your future. There will be roadblocks, but you will come out successful in the end. Why give up when you know the end will be fine. There can be surprises, but never give up hope. And lastly, be grateful for the life that you have.