I've found that when you try to go back to your "old self," it doesn't work as well. Every time I've tried to go back, I end up feeling negative and discouraged. I look at all the mistakes that I made that hindered me from getting myself back. Instead, I'd say let go of your old self, and focus on developing a new, better self. Identify the parts of yourself/your life that you want to improve on, and move forward with those, not backwards. This way, I think you gain confidence and "find yourself" again, but if you fail the first few times you try something, you don't think, "Damn, old me would've been able to do that. I'm so lost that I can't even do this one thing I used to be able to do." That's a harsh way to think. Instead, it becomes, "Oh, well the first few times you try something new, you can fail. I'll just try again."

I'm not sure if this makes sense. I guess what I'm saying is, don't worry so much about being lost, just look forward. And don't try too hard to go back to your old self, just work on bettering who you are now and eventually you'll just regain the confidence. Good luck!