Hey Stephanie,
some answers to your questions:
"It just seems like when I do think about them, I feel as though when I do think about things and start to obsess, I get so down on myself because I feel as though I know so much better, like I am letting myself down.
Does that make sense at all?"
This makes perfect sense to me and anyone else that has ocd or anxiety. You know these thoughts are ridiculous and a far cry from who you are and what you want to do.
Beating yourself up though won't help out with ridding yourself of these thoughts.
I know when I beat myself up about having these thoughts it is out of frustration. I don't enjoy having these thoughts at all. If I had an off switch I would totally use it. But when I beat myself up it is self defeating like as if the anxiety and OCD is getting the better of me.
But you know, we are only human. You gotta expect to have your vulnerable moments. But that is when you have to be extra compassionate with yourself. This is not an impossible disorder to overcome, but it is challenging.
You ever beat yourself up after some of these thoughts thinking " What more can I do? why can't I just realize these thoughts are stupid and forget about them?"
I think that as you say you have come a very long way and understanding that it is not the thoughts but the reaction to it is a major accomplishment. You should be very proud of that in itself because it takes a while to get there.
Try and remember that the frustration you feel comes out of a desire to get better, and not as hopelessness. See your frustration instead as boredom. INstead of saying " wow! Why do I keep having these stupid thoughts" start saying " wow, I am really getting bored of these thoughts."
WOw the same thoughts you are struggling with are the same for me! Those are the big three for me also. Although I don't have a sister, and it is my family.
I know exactly what you mean about getting to the top and wondering like you still have more to go. I am not fully recovered but I am getting there daily. Hug yourself because you have already reached a point that some do not get to. You are at self-awareness. without self-awareness about this condition it is really difficult to get going.
Now you just got to work on changing that fear response into a mellow response. You will get to a point when these thoughts bore you. then you will have a moment when the thought will creep up back at you out of nowhere and your fear response will begin to start but you will stop it at the door by saying " Oh this again, good thing I remember that this thought bores me now."
That simple phrase helps me because I don't sit there entertaining the thought for much longer after that.
I don't know if you have ever noticed this but, you ever obsess about one of the thoughts, and say to yourself wow, why can't I be obsessing about the other one, that one is a little easier to handle.
great lesson in that it is not the thoughts but the obsessive thinking habit.
But I think you are well on your way. therapy is great because you have a professional opinion on the matters. It can be very comforting.
I know this turned out to be very long but I will leave you with 1 thing for each one of those thoughts you are dealing with that helped me and still do.
Thought of hurting yourself: You clearly want to get better. And ARE getting better. deep down you want to rid yourself of this other wise you wouldnt be in therapy or on meds, or on these forums. When you have these thoughts and doubts ( OCD is also called the doubting disease

)
just say to yourself "despite these thoughts, I just want to get better. And I will get better"
thought of hurting your sister : from the research I have done, including that article, I learned this very important and comforting fact " Obsession will never interfere with your genuine desire. Obsession will only keep you from doing things."
You fear hurting your sister. You do not genuinely desire to hurt her. You will never hurt her. The only thing you'll end up doing is avoiding her to avoid the thoughts.
No matter how much you obsess about hurting yourself or your sister IT WILL NEVER HAPPEN, because you have no true desire to do so.
Going Crazy: Both therapists I have seen, and all the books I have read say, you cannot think yourself crazy. you can only think yourself into more anxiety.
I know this was very long, but I hope it helps. You struggle with the same thoughts I do. If ever you have any questions about stuff. feel free to message me.
Take care,
Eddy J