My stretcher wont go through anymore?

Ok, so i got a new stretcher today, a normal long taper, my piercer told me the stretcher was 2mm, which was what i asked for. i used to have a 1.6 in, but this stretcher seems like three times the size of it, so im not too sure if its a 2mm. I began to push it through, it's quarter through already, but it won't go through anymore, is this because i am not pushing it hard enough or i haven't got enough lube on? It really hurts everytime i give it a little push, could i please have some advice, shank-yu