Can Social services take my children away ?

One would hope you'd look into putting Grandma into an assistance living center before you'd risk losing your children. 

maybe you should put her in a home

First off, DO NOT PANIC!

You say that although you have a mental illness, you have the support of mental health professionals and you are taking your medication.  And so YOU are doing everything right.

Your grandmother needs to be in a nursing home because she is total care.

If Social Services get involved, they will WANT YOU TO KEEP YOUR CHILDREN because you are doing everything right.  What Social Services may do is find you a bigger apartment (that is low income) so that your children will have their own rooms and get nursing assistance to come to the home to take care of Grandma (clean her, feed her, get her in the shower, provide one on one care).

As it is now, you cannot leave grandma alone and social services can provide for that, too.

And so if I were in your shoes, I would look to Social Services as a helping hand in this case.  ASK what they can provide for you to help.

Watch out they will take your children and you may never see them again.  Have a family member take guardianship for safety sake.  Good Luck and God Bless you.  I know it will be hard to pass them to a family member but it's got to be better than never seeing them again.  There will give your children up for adoption fast.  I know because they came after my twelve year old son...they didn't seem to care about my older son but Luckily I had a power of attorney saying my sister can take care of my children if anything happens to me... I have depression and have been hospitalized at least once.  I didn't get my son back until he was eighteen but at least the power of attorney stopped them when they took him and tried to give him up for adoption.

When you use the term "flat", this usually means you aren't in the US.  This matters, because we don't know what services are available.  I do know, though, that all countries have ways to intervene when children are at risk.  It sounds like yours are.  Why on earth did you bring a baby into this mess?  Are there any fathers floating around who can help?  Also, on grandma, at her age it's very possible she's got dementia or Alzheimers.  It's not the memory fading that is noteworthy, since this happens at her age. It's the outbursts.  These will get worse if she does have one of these conditions.  And she won't remember any instructions you give her on child care.  All I can tell you is that in the US, this is very much a situation where kids might be removed.  

Yes they can, if you or your environment is dangerous to them.

Yes, they can, but it is both cheaper and easier to support you in keeping your children.

If you are managing your mental health and getting support, then it’s unlikely that’s what they’re pushing for. You just might need extra support in other areas.

Only time will tell how this will work out.

It is the duty of social services to check out the situation whenever a complaint has been made, but they don't like to take children from the parent(s) as long as the children are safe and taken care of.  It is too hard on the children to remove them unless absolutely necessary.

You should contact social services yourself - it sounds like you could do with extra space, and social support with regards to caring for your grandmother.

Social services take children away as a last resort; if you take steps to support your family, this is a good thing. 

you DO need help. tell social services all this and see if they have any suggestions about what to do about your grandma.