There always be doubt in either failure or success. Will you get back on your feet after getting knocked out? Will you managed to create better than your former self? There always be doubt and it’s normal.
All we can do is just to charge pass thru it. The road is supposed to be hard, rocky, non linear or whatever. But that road leads to your goal. It is the right road. The best thing you can do is to focus on your step, one at a time.