I hadn't noticed an absence of support information as you say, but that doesn't mean what you say isn't true. I do think that for "adults" any abuse can often be dealt with through the victim's funding and resources.
I do think that people are less understanding of trauma with adults though, yes. And their saying anything like you were old enough or big enough to fight back just shows their ignorance about such matters. If you're being victimized, the trauma reactions are often the same.
I'm sorry you are having difficulty. How can we help you here, can you offer suggestions?
(((safe hug)))