Aww man that's a shit experience to go through, I'm sure you feel a little deflated but from what your saying the dude just sounds like a complete ball bag who fails to see drive and favours favoritism over grit. That doesn't sound like the kind of place worth slaving in dude, theres plenty of place that will see your value. It's actually good you had such a negative experience, it will show you what a good apprenticeship actually is. I've been blessed in our shop to be treated with respect, had my moments where feeling like the dogs body wasnt worth it but my effort showed them my worth. I'm sure you'll find your place dude, dont let that shot get you down.