@catmom777 I doubt there are many parents alive who do not have some guilt about things they did and afterward regretted. Our kids are generally wonderfully resilient and forgive. If your ex-BF did something, then don't blame yourself. You did not do it.

As others have said, it is time for you to forgive yourself. You have made amends to your daughter as well as you could and she has accepted that if she lets you into your grandchildrens' lives. It is history, yep regrettable history, but it's done, your daughter has gotten on with her life, you need to also.
Hugs, JK