i cant focus

I know I have A.D.D but just today only I've been having the worst time just trying to type a single message to someone else without ending up talking about something completely different.i don't know what is going on,this has never happened to this extreme. I will try to write something like " what should i wear?" but then i look and I wrote "What should i watch" not exactly what i was going for. I just cant seem to keep a hold on my train of thought when messaging someone. Its not every time i type,obviously I'm not screwing this up,but its happened a few times where i just couldn't get it right.