At a wits end

Ok I'm literally exhausted and I don't know what to do. My baby is 4 months old next week and she's been tough lately and that's putting it lightly! She is going through this phase where she cries and puts her hands in her mouth and sucks so I offer her milk. Everytime I pick her up or sit her to feed her, she starts screaming and throwing herself about. I try and wind her, I change her nappy and I do bicycle legs but nothing seems to work. If I just hold her, she tries to chew my face or sucks my arm and it's a vicious cycle. Her sleep pattern is changing also; before she used to fall asleep back on the bottle easily but now it takes me up to an hour to get her back to sleep and by the time I've then got back to sleep, she's up and fussing. Just now it's taken me two hours to get her back to sleep battling between trying to give her a bottle, burping her and just cuddling her. Anyone else been through this? Is this normal?