Hi Bcasey415
Croix offers great advice. Personally, as a mum, I would be feeling the same. I'd be feeling upset in regard to my child having felt such ongoing stress, holding this secret in for so long.
Of course, I'm not your dad so it's hard to say how he will feel when you tell him the truth. What I can tell you, from my own point of view as a parent, the news that my child did not actually experience such trauma would come as an overwhelming relief, outweighing all else. Dealing with the lie would be secondary to that. Parents often see themselves as protectors and can sometimes feel a sense of failure in not being able to protect their child. In telling your dad the truth, you may actually be releasing him from some sense of failure he's been living with over the years. By asking you occasionally whether the incident really happened, maybe he'd always been hoping you'd say it didn't.
Personally, I see forgiving as moving forward through giving release from something (including the negative energy that that something generates). Once the truth is revealed, everyone will be able to move forward through letting go of one thing or another. This is the ideal scenario, though it might take a little time and work.
Might be easier to speak to your mum first? She might have some insight regarding how to best approach your dad. No matter which parent you choose, perhaps the best way to start the conversation is with gratitude. For example, 'I have always believed in how lucky I am to have you as my mum/dad and I love you so much. It tears me up inside to think of the stress I have caused you over the years regarding that reported incident when I was 4. I need to stand up and take responsibility for this now, rather than let it go on any longer. It has reached to point where it is causing a deep depression within me.' Expressing to your dad that you know he does not like lies may help. Telling him that you wish to now replace the lie with responsibility may have him look at things differently, with some respect. Not sure. Telling them the extent of the pain within your self may also give them insight into how tough it's been dealing with this. Transparency can help on the path to regaining trust.
Bcasey415, in my experience, depression feeds off lies. Depression can't survive within truth. Seeing lies distort how we see our self, it's so important to get rid of the distortion, in order to become our most authentic self, free of suffering.
Take care
