You are right - it wasn't a wise choice, and I wouldn't do it quite like that again. And yes, a sitter is, in my opinion, essential for such activities.

I've never quite reached that place through meditation. Though now that I think about it, exactly what sort of meditation makes a difference. I've never had anything like this with mindfulness - but 'striving' for a particular state in mindfulness can be kind of self-defeating. Either way, I would think it's possible.