Laurabunting I am so sorry you are in this situation. You may not be able to say what the problems are.
I must agree with Jidgetbones, Tanfastic and Hangtidy (in no partictular order), they have given good advice.
If social services have removed a baby from you then if you get pregnant again they will investigate again to see if enough things have changed in your life to mean it is advisable to let you keep the next baby.
As I am sure you know, babies are not replaceable. You cannot have another one to heal the hurt you feel from the loss of the first one. If you want to parent your child, please do all you can to get back the care of your child. If this is not possible you will need to allow your heart to heal a little more, and your circumstances to change enough for you to be able to keep your next child. I sincerely hope you realise I am not saying this to be hurtful. It is possible to move on in life, I do believe it will help you to move on in life if you have done all you can, even if you do not get your child back.
I would do everything in my power to keep my child. I have two children, one birth child and one by adoption. I would do whatever it took to keep either of my children. Be it counselling or therapy, medical or practical help, moving home or leaving my husband (if he were the 'problem') or cutting contact with my wider family (if they were the 'problem') in deed as someone else said, 'any adult'.
Of course I would want to identify what exactly was the problem before I started leaving places or people.
You really do not need to say more here if you do not wish to, but you do need to know for you.
The only situation I would not do this is if I felt completely and utterly that I could not care adequately for my children. And if that really were the case, I would not want any more.