Vet surgery costs

Yesterday I found a lump on my dog Archie who is 8 years old. After having him shaking all through the night and then unable to walk this morning I took him to the vet to be told that he has a tumour in right testicle and needing surgery which he will be going in for on Tuesday 07/01/2020. Today he recieved pain medication and injection which came to £172 alone. As I’m not started a new job until 06/01/2020 I’m starting to worry regarding the surgery payments. I have put a base down of £500 as I don’t have the full amount of how much it’s going to be yet, but I know it’s going to be atleast that with the figure the vet gave me.  I’d be grateful if anyone could help at all even with the littlest of payment towards getting him the surgery he needs. Any paperwork people would like to see regarding the payments can be shown.  

thank you in advance, 

Love Archie x