First, I'm curious about your profile picture. Are you a skater? The reason I ask is that when I was a JW kid, forced to attend meetings from the time I was born until I left at about age 14, my parents wouldn't allow me to play any sports at school, so I got into skateboarding, and became quite good at vert skating. I'm an old man now but I can still do pretty much anything on a skateboard that I did as a kid. I ride at skateparks about once a month or so.
But seriously, my dad was an extreme JW as well. He ruled our house with an iron fist. Any disobedience was dealt with physically, including complaining about going to meetings, etc.. And you didn't dare say you didn't believe in the cult that calls itself "the truth."
Your dad's arguments are BS. The claim that creation is "self-evident" is crap. Just because something is complex doesn't mean it had to be created by an intelligent being. Nature tells us that. Did your father ever consider the possibility that understanding the origin of mankind is beyond human comprehension? No, he just bought into whatever the corporate cult that calls itself the "truth" had to offer. It might surprise him if you focus on the reality that the bible was written by man, not the fictional god therein. And the Bible's claims that it is "inspired by god" are not authenticated; meaning that there is no independent evidence supporting such claims. Email me privately and I'll give you plenty of questions that Dad won't be able to answer without using my dad's favorite response, "I'll look into that and get back to you." Somehow, he never does get back to me on those questions.
At some point, you're going to have to stand up to dad, just as I did. It cost me a broken nose, but it was well worth it. Since that time, I got my education and have been successful professionally, financially, socially, and last but not least, physically. My parents got used to dealing with me on my terms, and now we have a very good relationship, even though dad is still a JW elder.
You're at a tough point in life. Life is no bowl of cherries, especially for those of us who were raised in this miserable cult. My best advice to you is to keep questioning the beliefs that have been carefully programmed into you by the Watchtower cult. As you pointed out, you often feel that the JWs might be right. That feeling is the result of very good brainwashing strategies employed by the Watchtower cult. How else would they survive if they didn't consume the lives of the youth? Ask dad for a copy of the Watchtower corporations' financial statements. I've never seen them and I believe that their failure to disclose them is attributable to their desire to keep secrets about compensation and perks given to the higher ups, from the "great crowd" of pigeons who pay their way.
Finally, put everything you've got into your education. It's your best chance to escape, as well as to do something that will make you very happy in life. While you're at it, don't forget about physical exercise. Strong body and mind will keep the Watchtower plague out of your system. Please feel free to email me if you have questions or would like to discuss anything privately. I wish you the best of luck!