Oh no - been there, done that more than once :lol: Whenever I've done that, if I have another, I've tried again so that the bun gets continuity of treatment. Just ring the surgery in the morning and tell them what's happened and ask for another one.
Two little tips that helped me - when you pinch the scruff, I found it helps to use your index finger to push inwards to make a little divot to guide the needle into. Makes it far easier to see where it's going and prevent it from getting right through.
Second, once the needle is in, just draw back slightly on the syringe. If it's in the right place (and not in a blood vessel), it should be a vacuum and the syringe should suck itself back in to where it was before. If it sucks up a load of air you know you're not in and will need to withdraw and reset the needle.
Good luck :wave: