Happy Shoes Undone, Aylesford

So Wednesday morning had to do some family stuff instead of going to work. During said family stuff my back went. Managed to shuffle around, painfully, for most of the day. Come Thursday morning the stabbing pain was so bad when I tried to move that I may have yelped very loudly indeed. Not good, particularly as it was three o'clock in the morning! 
The pain is always on one side of my lower back and the ache runs down my leg towards my knee - I've read this is a classic sign of sciatica. All I could do was ice it with frozen peas wrapped in a tea towel, aided by painkillers, which is the treatment which has worked before. By later in the day I could at least stand but couldn't put on any socks or footwear. It meant I couldn't cheer myself up with wearing my happy shoes (see above) and I certainly could not have tied the laces. Trying to get an appointment with our local doctor's is almost impossible (it's usually a two week wait and often they won't see you face to face) so I've looked up some exercises on line and have started trying to do them today.
The bit I hate is having to tell my boss that I can't make it into work. He's warned me before that he cannot protect me due my sickness record which makes me feel very guilty even when I know there is nothing I can do about it. I dread the phone call where I can tell by the first few words that he is angry and pissed off with me.
Over the past few months I've been thinking hard about my job and the commuting and whether I want to continue. With his reaction and the general work situation I don't know if I really want to do it anymore. I take a great deal of pride in doing my job properly and to the highest standard I can but is that enough? I'm more and more unsure if it's worth it.