You're being too hard on yourself. Back up and take a deep breath. "Expertise" comes with lots of practice, practice and more practice. Perhaps you've jumped the gun a little and have started with something that takes a little more experience. Take baby steps and work yourself into the more difficult blocks. Certainly don't quit. I know it's frustrating, but we've all been there. I was there last night. I was making a BOM for my guild and was about to pull out my hair. The points all came out fine, but the block is the wrong size. It's a Civil War block and was made using templates. I'm a strip piecer so those many little pieces were a nightmare to me. I know what went wrong, but it's all together and I'm not about to do anymore ripping. It's a basket block and the problem lies in the basket -- the pieces are too big. I would have needed to take larger seams (I had used a scant quarter inch). I have two choices: to make another block (will have to wait until all blocks are made to see if I have enough scraps to make another block; OR I can just cut off the points at top and bottom of the block. The sides are fine. And I think I will choose the latter. I'm not at "proud" as I used to be and it's just a quilt.
Good luck in your endeavors and kick back and enjoy the ride.
Bottom line is, you'll learn from doing and each one will be easier and better.