You are correct,,,, DUH.. I change it to wasn't..I assume you mean it *wasn't too good to be true? The way you worded the sentence makes it seem like "actually was" refers to the concept of "too good to be true," rather than simply "true." So, "actually was true" would be clearer. Even "actually wasn't" wouldn't have made me scratch my head.
Maybe I'm just a weirdo and everyone else gets what you mean. Where's that hiding-under-the-chair emoji when you need it?