A drunk man who thought his girlfriend was cheating on him splashed petrol over her and tried to push gravel down her throat, a court heard.
The 41-year-old victim was dragged from bed and punched and kicked in the head, Caernarfon Crown Court was told.
Darren Jones, 31, of Arfryn, Bull Bay, Anglesey, admitted assault causing actual bodily harm and criminal damage.
He was jailed for 20 months after the court heard his girlfriend feared she was in real danger.
The court heard that Jones's girlfriend had gone to a neighbour's house on 1 October, dishevelled, distressed, barefoot, bloodied and with a black eye.
Judge Huw Rees said: "It's difficult to imagine a more serious example of domestic violence."
He imposed a 10-year restraining order to keep him away from his victim.
Sion ap Mihangel, prosecuting, said Jones, described as having a history of cocaine use, was convinced his terrified partner was cheating on him.
Richard Edwards, defending, said: "It's very difficult to reconcile the difference between the quiet, polite young man and the man described to the court by the prosecution.
"He's no particular explanation for his behaviour other than the effects of the alcohol. He has no previous convictions for offences of violence."
The court heard that Jones, who was self-employed and had met the woman on Facebook, was ashamed and had apologised for his behaviour.