helllpppp

So f ing tired! Starting to feel like my baby would be better off with out me!
I live with my mum which is really useful.
Mums a Christian and I'm not. She keeps saying I need to pray for protection!
It's 4.42am, baby's been awake since 3! She's 6 months old! Was sleeping through at 3 days but is now teething!
Mum came in about half an hour ago and made me jump checking that when baby's in bed with me she doesn't "have a phone charger round her neck" when shes in bed with me. she also woke baby after I'd just put her in her cot.
So I snapped at mum saying u keeping waking her up opening the door. 
So she said Sorry I'm just checking she hasn't got a charger round her neck
Feeling like I can't do anything right