Well here we are, 3 days on, and still can't really understand what the hell happened. Didn't do anything out of the ordinary on Tuesday and went to bed feeling fine. Wednesday morning, woke up, stretched a bit, then went to get out of bed to be thwarted by horrendous pain.
Tried to stretch it off a bit, tried again, couldn't do it. After half an hour or so of trying, called down to dh to help, but couldn't stand the pain of trying to sit/stand.
DH took the kids to school and I tried to wee in a nappy (not to be recommended, but needs must) and I posted here. Then phoned 101 and waited for a call back. After an hour or so I really needed to get to the loo so dh pretty much dragged me screaming at which point 101 rang back, dh answered, I used the loo and just slid onto the floor as no pain when laying down, and spoke to 101 when I'd stopped sobbing.
She'd obviously heard the commotion and was concerned, but on the floor I wasn't in pain at all. Said choices were a visit from gp or paramedics as I couldn't stay on the floor (I disputed this bit, as fine on the floor). Anyway an ambulance arrived, had check over and gas and air to get back to bed - advised to take some when laid down before movement and it really does make you giggle when you're not in pain - such a twat!!
Anyway, not so funny when I did move but managed to get back to bed, gp prescribed diazepam and strong co-codamol over the phone and dh dispatched to collect. After a couple of hours the painkillers kicked in and I managed to get to the loo again and slid down the stairs - was pretty much out of it for 24 hours and slept a lot. Then Thursday afternoon suddenly felt a lot better, could get up and move around with a little help, Friday was even better and although still feel a little stiff today, all is well.
Paramedic said it was probably a muscle spasm, probably was, it's gone now thank fuck, and the whole episode seems a bit unreal. Feel ridiculous that an ambulance came out, but with hindsight I did need to get off the floor at some point although probably would've been able to do it a few hours later once pain relief had been given (assuming of course that gp could visit).
Thanks to all that commented and advised - it says something that I thought to post on here without 111 crossing my tiny mind! Really hope that it doesn't happen again!