As he no longer holds any military titles, he can't wear military uniform.
However, like all ex-servicemen, he remains entitled to wear his medals (and, contrary to the idea apparently behind your question, there's been no suggestion that he should 'lose' them).
Why would he want to? He’s no longer a working member of the royal family so would have no occasion to wear a uniform ... unless he went to a fancy dress party maybe.
As tambourine says - Harry only has 3 medals that are not honorary and he is entitled to wear them. The rest of the regalia does, however, have to go. The Queen did, it is reported, tell him that he couldn't be half-in. He made his choice, but I'm not sure he understood what it meant.
I think he has been given a rotten hand in life, I feel very sorry for him.
Everything seems like Greek tragedy being played before a largely hostile public audience.
I agree that losing his Mother must have had a profound effect on him and his brother.However,his choice of wife and subsequent actions are of his own choosing.I think that he is so besotted with her that he goes along with her because given his military career and love for his grandmother he would have made these choices to distance himself from his family.
I think the public only became ‘largely hostile’ when he and Megan started behaving the way they do.
Prior to that I believe most people were very pleased he finally seemed to have found what he was looking for and were right behind him. I was one of those people, but now I don’t even bother reading much of the stuff about them.