Yes it will definatley be panic, I get exactly the same and you would think after all this time you would know the difference between those pains but you really don't! You said yourself you were...

Don't panic, I'm sure your mum is fine to look after him if she has been up until now, will she be ok to look after him there? does she know how bad your phobia is? If so, try to relax and remember...

I am a receptionist at an animal rehoming center, quite suprised at the amount of nurses and things like that, you are all very brave lol!