She expects you to roll over because that is the precedence you have set by your behaviour
Right now I don't think she cares why you move out. You could say something like 'I'm going to have a think about wether I want to stay here or move, I will let you know' Have you stood up to her about anything recently? It sounds like she walks all over you and you just take it. You shouldn't get nasty but at least stand your ground on something that she tries to push you over with.
If you moved out could she run up a lot of debt in both your names?
M36 W31 S4 S2 T5 M4 BD Jan12 S July12 Recon Sep12-Nov12 ILBINILWY Jan13 OM x 2 in 2013 W wants R July 13 I start D. Jan 14. Meet GF Nov 13 Have I changed enough? Jul 14