Why do I feel like I will fail, if I don't know what is going to happen?

Because maybe you are thinking about "what will happen" and constantly thinking "what if?" you just gotta try and stay positive and paint yourself a positive picture in your mind that you will succeed! Because feeling like you will fail will only get you down and put you down, so by putting yourself down it wont help, hopefully you can try with all the positivity! :)

A lot of times we feel really down about ourselves or don't believe we can achieve the things we want. I think this is normal and you should not feel ashamed for thinking this way; although if you start to adopt this way of thinking as a mindset, it can negatively affect what you do. You'll start doing less because you only think that's what you can accomplish. You'll find your confidence shrink more and more. It's important to constantly remind yourself of the things you have achieved and want to do, so you know that you are capable and so that you can keep pushing yourself forward.

Self doubt and insecurities can be very hard on you. Learn to love and believe in yourself, don't put so much stress on the outcome that you deny yourself the journey.

you can try to reward yourself when you do something healthy, but most never forget the fact that everyone is unique.

its human nature. Don't worry. If you think positive you will have positive results. I truly believe that

It's because we always imagine the worst case scenario even before we start do it. That's what make we feel like we won't make it.

Sometimes we as humans we are afraid of failure and getting hurt that we build a wall around us by making sure we know whats going to happen before it does.And if we are unsure we tend to hold ourselves back. The good thing is you will remain safe and in the same position all the time and the bad thing is you will miss opportunities and will not move forward in life.

Because the not knowing is causing you to overthink and make you beleive you are not good enough at what you are trying to do.

Everything happens for a reason, it's okay to take a step back and relax. No one is forced to take something when they're not comfortable doing it.

Sometimes our mind plays tricks on us. For some reasons it's easier for our cognition to fail after we predicted we'd failed rather than to be optimistic about an outcome just to be let down later. Fear to fail can get in the way and affect what we think or what we can accomplish on a daily basis. Fear to fail is also strongely linked to perfectionism, which could lead to a general anxiety to lose one's control over situations. A good way to think of fail is that usually we can try and try again, having a broader spectrum of data to analyze to perform better in a future.