He was sitting behind me on the chair I went to stroke him and he lunged at my finger and snapped down like a crocodile

I think I startled him because he's a lovely boy.
This was at 10ish last night. A few hours later my hand went cold, tingly and at one point pins and needles also my arm ached I was up until 3.30am.
The bite doesnt look that bad but where the finger tip bends instead of being straight it goes downwards - the bend line that is. The bite is double and just over 1cm long it doesnt look to deep though. My hand still feels cold,achy & a bit stiff and my fingers a little swollen it's sure hard to type this cos it feels a bit numb too

Should I get a tetanus injection or anything

Thankyou in advance guys