Have I done the right thing?

A couple of days ago I reported my mum to child services for neglect and I'm really worried that I've just made the situation 100 times worse.

My mum has been an alcoholic for as long as I can remember but she always made sure that she cooked us tea when we were little and usually stayed awake until 7pm. 

For the past couple of years I've been away at university and over the last year her addiction has got worse. My little sister has downsyndrome and can't look after herself at all, she can't speak, or run herself a bath or cook herself a meal. Last week I went back home for half term and mum started drinking in the morning and was asleep by 2pm most days. I cooked tea most evenings and looked after my sister while mum was asleep and I'm worried that while I'm at university my sister isn't being looked after as it's only my mum and sister in the house.

I haven't told mum that I phoned child services, I'm worried how she will react if she finds out it was me who called them and I'm worried that a visit from child services will make mum's depression and drinking worse. I'm worried that my sister will be taken away from the family home because my mum is a great mum when she's sober and just needs some support and I'm also worried that child services will catch mum when shes sober and they will think things are fine and things will continue as they are.

I just want to get mum the help she needs but i think i have made things worse.