Hi! Are you using the mouse or a tablet of some sort? Tablets (either regular or screen style tablets) help you draw the way you’re used to— but digitally and they work with most art software. Ive seen amazing art drawn with a mouse but I personally found that to be ultra frustrating as I had a hard time controlling where my lines went. Tablets helped make that a lot easier.
Also— if it’s the software itself that you’re finding to be a little frustrating, you can search for basic usage tutorials on the internet and you can learn a lot from them. I’d say focus on the basics: using layers, and brush tools. Once you get the hang of the basics, you can branch out to whatever you like such as painting, or using the pen tool and such. I hope this helps!