Totally blanking all of my efforts to contact her. Not done anything as far as I'm aware but have begged her to tell me what I've done and have apologised for inadvertently upsetting her and asked if we could talk.
That's quite full on. It may well be that something was going on - anything, really - and now there's a huge amount of pressure to respond. It could be that she'd just forgotten to reply (not great, but not rare either, everyone has frantic weeks), or that something personal happened, or something happened at work, or she was anxious, or she just needed some alone time... and now it's something huge, she needs to explain herself, she can't just pick up where she left off.
Or it could be that you have upset her, or annoyed her, somehow - and whilst it may have died down, it won't now that it's huge.
Last option I suppose is that you've done something that has completely offended her and she never intended to talk to you again, but it's highly unlikely that you would be able to do that without having any idea what you'd done, so this is by far the least likely option.
Your only option is to leave it, really, and wait. She will, hopefully, contact you once things are calmed.