Growing into a new function at work

Lately I have been shifting my function at work. The last few years I was a designer and drawer at a design company. Now I got the chance to grow into a new role. I got the chance to become a projectleader, have contacts with the clients, have someone to help me with the design and make my own projects. I have been doing this for 2 months more or less and step by step I am learning about it. But it also stresses me out a lot. I am very scared of making mistakes. I guess my fear is to fail so hard, they will not let me do the projects I would like to do or stay at the office. I would like to find a way to shift my mind, to find confidence in me doing these new things. Can you help me with finding the best way to do it (course – study vault). I already did some thought downloads and models on it, but it would be good to dive deeper in it. Thank you.