I think your dilemma is that you want to get rid of him, but don't want to embarrass him. Therefore, slowly alienating him may be the best choice. For example, if he asks you to play, you can say that something is wrong. Over time, he will stop asking you out.
However, I still advise you to reflect on yourself. 10 years of friends is hard to come by. Be tolerant when making friends. For example, you say that he "doesn't know how to dress up, but he cares about his image", which is not a shortcoming in my opinion. Maybe it's just your own subjective opinion. If you think about it from his point of view, maybe he is not as disgusting as you say.
In addition, there are many kinds of friends. You don't have to be friends or strangers.
You're only 19 years old, and it's time to be in high spirits. Don't be impulsive, think more rationally before making a decision.
Life is a choice, isn't it?