Experiences of epidural, please share

Hi all, I'm currently being investigated for some health complications which may mean I have to have a c-section. I'm quite scared of having both a section and an epidural for a few reasons and wondered if you could share your experiences of the epidural in particular with me so I can understand what to expect. I have previously had a slipped disk and worry it would aggravate my back again as I hear this can happen. Is it painful to administer and did you find this manageable?  How long were you numb for?