It's happened to everyone Boardgirl, everyone new to SPDs...even those who don't admit to it. Try not to get too angry about it.
Bikes are tougher than you might think and the LBS, all else failing, will get your gears back in working order.
(I presume you do know that on the rear of the pedal, or somewhere according to make, there is a tension adjuster, which with a little adjustment eases up the cleats a little. I have mine pretty loose for precisely the reason I don't want them too tight).
All the best.
Thank you Monsieur Remings I just feel frustrated with myself, probably mainly because I'm embarrassed and keep cringing. I know it's just 'one of those things' but when it happens it's not nice.
I didn't know about the adjuster on the pedal, will take a look at that.