What if it didn't matter if you have all the answers right now? What if it was OK if you accepted your current situation for what it is (i.e. simply a mixture of circumstances and emotions that are subject/likely to change)? What if all of your reasons haven't even been born yet? What if it was OK for you to be where you are with no reasons whatsoever?
My point is you can start by asking yourself different questions. I noticed that your questions centered on potential negative outcomes. Try flipping that around. "What if it was OK for me to feel this way right now?" "What if I don't need to change anything within myself right now?"
Better yet, take a break from asking questions for a bit. Take a few long, deep breaths instead. I have trouble remembering this sometimes, but life goes by one moment at a time. We don't have to live it all in one breath. We don't need to bear the burden of the next 60 years of possibility in the next 60 seconds of life. Take it a step at a time.
Try to not fight the feelings you're having. It's a battle you can't win. Accept them, let them be. The more you fight them, the more they'll consume you.
Try not to be so hard on yourself. You're only human. You'll never have all of the answers.
Finally, take everything I suggested with a grain of salt. I don't know your exact situation. I'm not a professional. I only know what's helped me get through tough times. Hopefully some of it can be helpful for you too.
I second the comment re: depression. If you've never spoken to a professional about these feelings, why not give it a chance? If you have, and it didn't work, why not try someone else? If you can only do one thing, speak to a pro.
I'm happy to share my own experiences/challenges with you if it helps. If you want, email me the things you're afraid to tell others about for fear of being rejected. It's my username at my username dot com. There's always someone willing to listen with an open mind, despite what you might think. Even if it's just some random stranger from the internet :)