Help - rock bottom and desperate

Okay this is a long one so I’ll do my best to keep it as short as possible. I’m sorry in advance but I need help and advice. I’ve probably missed bits out but I’m so drained.

I’m from the UK but live in Australia. I’ve been here nearly 3 years and I’m currently waiting for my defacto (partner) visa to be granted. I’ve with my partner just over 18 months and I’m 26 weeks pregnant with his child.

I’ve come to the realisation that he is so unbelievably abusive towards me. Not physically but mentally and emotionally. He gaslights me and manipulates me regularly and the worst thing is, he’s in complete denial and doesn’t even know he’s doing it. I’m pretty sure he’s also a compulsive liar. I haven’t got the energy to go into detail but the verbal abuse I get every time he drinks is so demoralising and disgusting. The latest being he’s accusing one of my best friends of telling him I’m not happy with him and I haven’t been for ages and I don’t love him, the only reason why I’m with him is because I’m pregnant. None of that is true, but apparently i told her all of that. I love him but pushing me away with his behaviour. He refuses to listen to me or believe me. Instead he’s just been texting me abusive messages over and over. He says it’s over and when I asked him if he’s 109% sure he had the nerve to ask me “how dare you?”

He tries to justify it by blaming his past - granted he’s been through some messed up stuff but he won’t get help. I’ve suggested counselling or a psychologist but that just caused another huge fight.

I’ve completely lost who I am. I’ve lost my independence, I’ve lost myself. I’ve lost my confidence. I hate myself for getting into this situation. I’m really at the end of the line. I can’t see any way out. I feel so trapped.

I need to leave him. There is no way I can stay in this soul destroying situation. Especially now I know I’m having a girl and it would kill me if she was ever being treated like this.

However...

1. We share a lease and he’d need to sign and agree for me to come off it. I honestly don’t know if he would agree to that.

2. I work for him so have no financial independence - can’t afford anywhere on my own and I’m not eligible for any government help because I’m not a resident

3. I want to go back to England for good and cancel my visa (even though it cost me all of my life savings)

4. My family are clueless this is going on but I’m desperate to reach out to my mum. We’re so close but I’m scared I’m going to disappoint them and/or upset them.

5. The prospect of being a single mother terrifies me

6. I have a car and a dog, just a lot of things here so leaving him and moving back to England would be quite a lengthy process.

7. I’m not a very strong character anymore, I don’t even know if I have the balls to do what I want.

8. Legally can I go back to England with the baby seeing as she’s not even born yet?

Please don’t give me any hate, I already get so much from him and I don’t think I could take any more. I feel so stupid and devastated 😥😥💔💔