Can anyone please help me to get out of this extremely depressing situation in my life?

Your past is your past. It's part of who you are and it's shaped you into who you are now. From what I can tell you're happy with who you have become for the most part. There's nothing you can do to erase the memories of the past. What you should do is embrace the past and use it to help you move forward with your life. Of course you're going to be nervous for a job interview! who wouldn't be?! But, get out and go for it. It's the only way you'll move on, and this is the best medicine for forgetting your past. You won't look back on it with so much pain then.