Opinions please driving me insane

So my partner and his ex have a shared custody of their dog. I do not mind this pretty simple Sunday-Wednesday/Thursday evening he has the dog Wednesday/Thursday until Sunday evening she has the dog. This is not my problem I get it they both refused to let go of the dog, the dog is loved dearly. Now my issue here is the ex! She's constantly on the phone to my partner crying. They have a joint bank account for the dog for vet bills, dog walkers, groomers etc... Me and my partner have been together for nearly 2 years now and she's the biggest reason we argue we don't live together no children together no future planned because I can't deal with the arguments she phones him in tears over me and my partner moving onto our next milestones I used to stay over at his until I was fed up of the calls her crying because "it was there first house together" she calls my children names she calls me names and he does nothing but try and calm her down don't even stick up for me nothing because he "doesn't want to upset her" I've never met the woman or spoke to her but as far as I gather she's a snobby fat cow (his words not mine) They are ridiculous over the dog aswell he's at her neck and call and I'm at my wits end our relationship is shit anyway without her he's manipulative controlling I literally have no social life anymore or he accuses me of being a bad mum and an alcoholic im not allowed to work incase there is fit men but he doesn't want me to sit on my arse all day he tells me I don't do anything for him but he moves heaven and earth for me but I can't seem to let him go everything I stick up for myself and leave I end up somehow chasing him and begging him for us to get back together I've no idea what is wrong with me. He's physically hot me and then phoned the police to say I've hit him and he's a victim even though the police saw the marks on me and finger prints around my neck they wasn't interested in the truth told me I was lucky he didn't want to press charges. I feel like I'm going insane completely sidetracked from original problem but I can be here all day complaining