Mary, I'm a firm believer of the '10 foot rule' If it looks good from 10 feet away - it's good enough for me!!
Also, as someone stated earlier, after the whole is made the big mistakes you thought you made will be hard to find. Don't be hard on yourself, we are supposed to enjoy our addictions!! Have you thought to take a class at a local shop or looked for a person to help one on one? Do you belong to a guild? Ask there for help with your cutting. Quilters are always ready to help - you just need to ask.
Good luck and post a pic when you get a few blocks done. I'll just bet they aren't as bad as you think they are. We seem to be harder on ourselves than on others.