I can't stand my boyfriend's bad hygiene

I am in a very committed relationship. The guy I love is a really wonderful one and very sophisticated. But, there's only one thing that bothers me about him: he is not clean and he doesn't care about his look whenever he comes to see me.

I have tried many times to convince him to change the way he looks but it's never worked. Once we had to break up because of this.

I know appearance is not important but still we as humans need to look neat and clean. Please I need help I can't stand the guy for this reason. What shall I do?!