That's a really sucky situation, hun. You've obviously been through a tough time with all that. You can be thankful now that it's over...at least the actual occurrences are over. It's good that you were brave enough to type this out, and to tell your mum. Those things are both good and show strength of character on your part. It's not your fault what happened to your dad. I guess it just turned out that way. You didn't really have any control over that. There's no need to feel dirty about it. It's not like you chose it. You said yourself that you'd kick and scream to get out of going to see him. It sounds like you didn't want to go there at all. The fact that there were "gifts" that accompanied that doesn't make it anymore that what it was - against your will and something you hated.
You were very young when that happened so you're tough for getting through it. It's normal to feel down/upset about stuff like this. IT's all part of moving on. Remember that you didn't choose this, and it certainly wasn't your fault. It was a terrible thing for him to have done to you, but thankfully, you won't ever have to go through it again. Now, you have to focus on the rest of your life, and controlling the memories of those awful things and be content with it all(it sounds like you're doing really well at that).
I guess people do hear you now. And some did hear you back then. You have a voice, and you're a tough person for getting through this. I know it must be hard, but I won't pretend to know what you've gone through. Only you know that.
So there's really no need to feel like that. It wasn't your choice and the "gifts" were just a bi-product of something you hated and had no control over. That feeling is pretty normal though. From here, remember that it's not your fault what happened and you sound like you're doing really well in getting on with the rest of your life.
You're welcome to message me if you want as well if you want to talk about it anymore.
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99% terror free