It seems to me that all your reactions are perfectly normal and understandable. You also have the advantage that your daughter is looking quite up to doing well in the exam.
I would say keep hanging in there. The exam will be upon you sooner than your realise and then you can revert to life without the prospect of the 11+ hanging over you. In the meantime work with your daughter to ensure she is able to tackle the 11+ exam content (mixing past papers, learning exam techniques and being adept with vocabulary, mental maths, VR types etc.) but not to overdo it if she is almost there. Above all, try to be normal and enjoy life!