Why should be in contact with my mother? Long one!?

You left your mum a message - do you even know if she received it? You could try the Salvation Army to see if they can trace exactly where she is and, if they can, get them to p the message on about the blood test. I think there are a lot of underlying issues that you haven't mentioned as this set up seems so odd, - she left you just like that at seventeen? to go abroad? Whatever has actually happened she is supposed to be the adult and she certainly hasn't acted that way, life is tough without a mum who loves you but your mum seems to have cut you out of her life, do not use this as an excuse to feel sorry for yourself - carve out a good life for yourself (MS taken into account) and you can hold your head high. Good luck.