Is he really over him ?

Well firstly I give you evil eyes because you let the relationship moved way too fast. Basically, in your haste to move in, you allowed yourself to become more and more open to this person, believing that you are ready to handle a step like this. And because of that, you two are not close enough to even feel the connection between a close couple.
Do I think you two are in love? No. Harsh I know. But love is not just gushed up emotions. Its a state where you are willing to do anything, even sacrifice your own happiness to make sure the other is happy. From what I see, I dont see this. I might not know enough granted. But he doesn’t have the courage to give you the frank discussion about his ex? And Im pretty sure he knows that lies do not lead anywhere good.
And what about you? If you love him, why aren’t you able to look past this and start afresh? If you love him, then why does something that seems quite trivial to the multitude of problems you can actually commit make you so afraid of the possible outcome? A strong loving relationship can withstand a storm like this.

My advice. Understand where you made your relationship go too fast and tackle that.

It’s one thing to lie to spare someone’s feelings, it’s quite another to get caught and continue lying. I’ve always been a honesty is the best policy kind of guy in relationships, particularly since some of my ex’s are still and will foreseeably be very close and dear friends.

In your case I would definitely be concerned, but honesty goes both way, you need to make sure you tell him exactly how you feel and why. Do it in a calm and very reasonable manner not in anyway aggressive or confrontational. Make sure he understands how important what you’re saying is and once you’ve explained, get his side, from start to finish, even if you’ve covered some of it before. Whatever happens after, at least you’ll both be on the same page and know where the other stands and why. He clearly needs to understand your feelings. This is the kind of conversation you should both make time for and sooner rather than later.

One thing to consider, it’s possible he lied to spare your feelings as he said, but also because he didn’t believe you could handle the truth. If that’s the case you need to do a little introspection and reflection on how you’ve handled things as well; it’s still not appropriate for him to be lying, but if it was a reaction to how he views you that’s an important factor.

Regardless, remember be honest, calm, understanding, and accepting of him and he should respect you enough to do likewise. If he doesn’t, it’s time to move on and, better to find out now than later.