There's a difference between remembering the bad to stay bitter and remembering it to stay safe. You sound like you have a healthy dose of remembering to stay safe.
I wouldn't be convinced it wasn't him just because MIL thinks not either...and certainly no guilt! You would never suspect him if he has not (time and time again) given you reason to believe it so. Stay strong, sweetie - you are an inspiration to others struggling with similar issues.
