Hey KJC, I also used to feel exactly the same way as you do and believe me I have read a good few of your posts and you have not managed to offend me yet.
I used to always seem to be able to bring out the worst in others as they were often offended by what I had to say. I, like you could not understand why this was happening. I spent a long time thinking about what I might be doing wrong and then realized that my thoughts were simply working too fast for my brain to process what to say and before I knew it what I meant and what I was saying were worlds apart.
I however learned how to slow the whole process down and things got a whole lot better from there. I now find that I am able to hold my own in any situation without offending anybody unintentionally.
I do not know if this is the same in your situation, but it might be something to consider. Often as sufferers of this disorder we are so consumed by our own thoughts and emotions that we forget to put what we are saying through the 'social acceptability filter'.
I feel we should all be allowed to speak our minds as we see things, but unfortunately this has not been the case in a long time. I feel if everyone spoke exactly what is in their minds, at least we would all know exactly where we stand and there would not be a need to wear masks, but unfortunately modern society does not work that way and certain thoughts are best kept to oneself.
Well I hope this makes some kind of sense and can be of some help to you. All the best and remember, if you genuinely have said nothing wrong, some people are also just full of nonsense.