What do I do if my father thinks I hate him even after I told him I don't?

Start doing things he likes so it shows you want to be around him. Like ask to go fishing is he likes fishing or maybe he likes riding bikes, Drawing, photography. Hey maybe you'll even get a favorite new hobby!

I try to make him understand that I love him by acting. I plan something for the both of us, like going to a picnic, or maybe going to somewhere we both like. I'll make him a letter telling him how much I love him and how thankful I am for him.

You cannot control what other people feel or think. You cannot change it or affect it, hard as you might; only we change our own thoughts, only we change our own pereptions of the world. You have done what you can. For now, you can continue to just be there for him in small supportive ways, like sending a "I was just thinking about you" message now and then or offering to help out with little things like groceries. Just being a good, supportive influence is all you can do. If that does not work, you can decide for yourself if it's still best for your well-being to continue being supportive to an unreceptive influence, but it's okay if you want to keep being supportive even if he doesn't believe it. :) You do what's best for your own well-being. We can only hope that other people do what's best for theirs, like acknowledging when people love them.

Try to show him that you don't. Spend time with him, make him cards or gifts on birthdays/Christmas/fathers day. Prove to him that you don't and he should come around.

Spend more time with him and try to do the things he likes, like watching his favorite show together

Sometimes actions can speak louder than words. Maybe you should do something to try and prove to your father that you still care about him, like asking about his day or offering to have dinner with him.

Maybe he just feel that he's not connected to you closely.Try spending as much time you can with him and make him feel he's special. Try talking about your feelings about him.

Show through kindness that you don't, try hanging out with him. In the end though, you can't directly change his beliefs and you may just have to deal with whatever he chooses to believe.

Actions speak louder than words - speak to him kindly, offer help in his day-to-day or projects, offer genuine praise when it's fitting, ask him about his day, make him personalized gifts that show that you know his needs and care about his comfort, well- being and good spirits

Actions speak louder than words. Show him and go out of your way if necessary to "prove it". That being said, I wouldn't focus your attention solely on how to make him happy and focus on what makes you happy. His actions should not dictate your behaviour.