I think you should take a huge step back from this relationship. There is a difference between privacy and lying. You disclosed that you had been in relationships before him. The exact number of prior relationships should not be an issue. It is especially concerning to me that he is making such a big deal about a detail like this when you’ve explained your reasoning for telling less than the whole truth. Instead of responding with compassion and understanding, he’s coming at you with anger and accusations. This is not a good sign. I worry that he will hold this over you forever. I worry that he is looking for reasons to be angry and controlling.
You say you’ve been in a long distance relationship. You didn’t indicate how often and for how long you’ve actually been with this guy in person. If you haven’t been, I think you need to have some of that time to get a better sense of who he is and whether he is for you.
You deserve better than this.
I wish you well.