We all will experience doubt one time or another in our lives. The reason is because we are conditioned to think and believe in certain things and in a certain way. For example you were taught that doing certain things is bad and others are not. You also were taught many other things to do and believe.
Then once you got older you started to doubt your own beliefs. I am not going to pretend as if I do not have doubts at times. But you know what I do when I have doubts I push myself to silence the doubts. Because we both know they are not doing anything but holding us back. We are scared of what could go wrong or what could happen and etc.
You really should make smart decisions to go for what you truly know you are capable of doing. Things may not be going currently how you want them to and that is ok. Remember you are in control of your life not someone else or a family member who you no longer live with. Every choice you make will impact other aspects of your life.
So make better decisions to push yourself to silence the self doubt you currently have. Then take action and then you will build momentum to achieve better confidence and not have time for doubting yourself.