Does it mean a man doesn’t love you if he doesn’t reply to your messages?

In this case, the man may no longer have feelings for you, no longer wants to interact with you, and will never reply, forcing you to give up. If he still has feelings for you, even if he replies in time at the time, he will sometimes reply later. If he doesn't reply all the time, he just doesn't want to pay attention to you and will let you give up.