Know what you know and know what you don’t know. You don’t need to know every bit of information to make a decision or take action. If you can’t make a decision then learn the minimum amount needed.
Research, Learn, Ask, Search
Being comfortable is a luxury rarely achieved. Learn how to make a decision without being comfortable.
Not making a decision is worse than making no decision. A wrong decision is better than no decision. Make a decision, see what happens and then adapt.