Being screamed at because of heat bills?

Okay, I seriously don't understand my dad at all. I need to know if what he's doing is abusive/toxic/just straight up wrong.

I'm 19. We're in the UK and I know for a fact he makes six figures, and the current house we live in that was bought in 2012 wasn't cheap (about half a million back then but it's worth nearly double now). Though, my parents are now divorcing and he's buying out my mother's half of the house so he can own the whole thing and she can move out, and he's all pissy about that because he earns more than she does and she didn't contribute to the mortgage (a whole messy situation that I barely understand if I'm honest). Dad is now acting like he's broke and poor. The buying out hasn't happened yet but likely will in a couple of months when she actually does move out.

Our central heating is completely broken and our house is basically a century old with big rooms and shitty insulation, so it gets super cold - most rooms average around 12-15 degrees Celsius, sometimes less. (My room reached around 9 degrees Celsius one day last year.) We have to rely on electric radiators to heat up the place, but we get screamed at for 'draining his resources'. But if we don't the rooms are an almost dangerous temperature to be in. My mum tutors small children and they're reluctant to use the downstairs bathroom when they come over because of how cold it is. I myself have to reluctantly go there when the other bathroom's occupied, it's almost unbearable.

He claims the electricity bills are £1000 a month and that he cannot afford it, and every time he gets a bill is a nightmare. He usually ends up screaming at everyone (mainly my mum and me, my 16 year old brother doesn't use the heating much) for wasting his money, but my mum and I are both iron deficient and seriously can't live in a house that's only 12 degrees. With me specifically I also have an eating disorder that has contributed to me being malnourished and underweight, so the cold feels even worse for me. I'm only even living here because my health issues are making it nearly impossible to find employment (especially due to my lack of qualifications/experience). My mum just hasn't found an affordable place to move to yet.

Dad treats heating like a luxury. He would scream whenever I used space heaters and I used to get so stressed out turning them on. Now I just hibernate in my room with the radiator I had to buy with my own money because it's too unpleasant to be downstairs with everyone. (I'm kind of the black sheep due to my health issues making me 'unproductive' and 'useless' since I can't find a job, and everyone I live with looks down upon me for not being able to do much.) Additionally, my mum and I are adults and he often uses this excuse when I say it's neglectful to deprive us of heating.

I just don't get it. Dad makes no fucking sense. If he's earning six figures just where is the money going? Where the hell did he get £1000 a month from, did he just pull that figure out of his ass? Please tell me if he's being unreasonable getting mad at us for using electric heaters. Thanks.