I think everyone experiences this when they start. The only thing you can do is remember everything is practice, there will always be faults because you will never be a perfect artist. As a beginner you'll find that often it's extremely difficult or even impossible to create what you see in your mind but that is okay, no one becomes a great artist overnight. You need to accept that it will take many years before your skills have reached a level where you can create anything you want, but just trust that every bit of work moves you a step closer to that day. For now just do what you can, try lots of different stuff and always push yourself.
Your work is really good for a beginner so I wouldn't stress too much about whether you've got the talent. If you have an idea I recommend not starting with the impression that this drawing will eventually be the final drawing. Experiment on paper and in pixels, delete your work and start over, try different things. If you put too much pressure on the idea that you need the first drawing to be right you'll always hit a wall. Create many drawings and choose the best one.
And sometimes it is fine to abandon work. If the piece is really working out and you're enjoying it you'll always have the drive and energy to finish it. Treat your current period of work as experimentation and learning, rather than stressing about creating high quality completed works. If you're having trouble focusing I recommend just opening up your art program. Don't give yourself anything that will distract your eyes or your hands. Listen to music, podcasts, audio books etc. If the blank page is there and you're enjoying yourself you'll draw eventually
Also just one simple quick tip for critiquing your own work: Flip it horizontally. You will see it with fresh eyes and will be able to pick out the problems far more easily.