When Louise regained consciousness on the bathroom floor last month, she woke up wedged between her wheelchair and the toilet. The blood on the tiles told her she’d had another seizure. “I could see the red,” she explains. The size of the room – so small she’s not able to shut the door against the toilet when her wheelchair is in it – meant she’d hit her head on the fall down.

Louise’s ordeal on that bathroom floor lasted a couple of hours but it’s a snapshot of how she’s been living for months. The 33-year-old has multiple health issues – a heart condition, renal problems and epilepsy – but for the last four months has been housed in a dangerously inaccessible council bungalow in Milton Keynes.

On top of its tiny size, the bathroom has no grab bars – the basic adaptation that would let a disabled person move safely. To get back into her wheelchair in order to reach her phone to call for help, Louise had to yank herself up from the floor by her arms, despite being concussed.

But things get worse still. When the ambulance came, Louise’s worry wasn’t the blood from her head but how she’d even be able to get to the hospital: there is no way for Louise and her wheelchair to get in and out of her home. Go to the front or back door of the bungalow and you’re greeted by a large step – a steep drop – and no ramp in sight. To get Louise to the hospital to have her head injury checked, the paramedics had to put her on a stretcher and carry her over the step.

This is Britain’s inaccessible housing scandal: disabled people injured in their own homes and housebound. Louise puts it brutally: “It’s like [being] a trapped animal.”

Theresa May’s pledge to build affordable housing last week was quickly dismissed as an empty promise. But the deficit in Britain’s accessible homes for disabled people was, as ever, not even worth a mention. There are now 1.8 million disabled people in England struggling to find accessible housing, according to research by the London School of Economics, with disability groups reporting parents falling down concrete stairs as they struggle to move their disabled children, or wheelchair users stuck in top-floor flats.

Until this summer, Louise had been getting by living in her mum’s house, but when her health got worse, the makeshift access became impossible: for years, the only way for Louise to get down the stairs from her bedroom was by bumping on her bottom, one step at a time. The bungalow was meant to be a temporary solution. It had a hoist set up – vital to help Louise move – as well as a hospital bed fitted with an emergency alarm. But there was no adapted bathroom – that’s no wet room, no space for a wheelchair or bars – or even a way for Louise to get in and out of the front door.

Milton Keynes council says that it was the hospital occupational therapy team that carried out the initial inspection before assigning the property to Louise and that at that stage, it didn’t highlight any access issues. But one conversation with Louise sitting in her wheelchair makes it clear that this place may as well be an assault course.

The kitchen is tiny, big enough to get a wheelchair in but not to turn around or move. The bathroom is taken up by a bath – useless given Louise’s accessbility and seizures (“My consultant says if I have a seizure [in the bath], I could drown”). Without a wet room, Louise’s only way to keep clean is to do a strip wash twice a day: a sponge, soap and bowl. To wash her hair, she sits in her wheelchair and hangs her neck over the bath as her mum – currently doing “everything” for Louise – stretches the showerhead to reach her.

That’s the added strain: Louise has no social care in place to help her wash, dress or cook meals. She cancelled the original carers sent by the council – she tells me that male carers would often turn up to help her dress, or she would be given a bed pan rather than help in the bathroom – and is applying for direct payments: the system that is meant to give disabled people the right to choose their own care. But she’s been told this could take months to come through. (The council says the direct payments process is still being followed but if and when it’s agreed, it should take two to three weeks to set up.)

Living like this is the definition of being stuck. Since moving into the bungalow in June, Louise has only been outside five times: each a visit to a doctor, physically carried out by ambulance staff. The ordinary parts of life – a friend wheeling her round the shops to look at handbags, or going for a coffee with her mum – have been taken from her. “I have to stay in. Permanently,” she says.

When I ask the council if there’s anywhere else to place Louise, they say they have no other wheelchair-accessible accommodation available and are “unable to predict when something will be available”. They’re not alone. The nation’s gutted social housing stock is routinely leaving councils with no accessible housing for disabled tenants, with wheelchair users up and down the country stuck in unsafe accommodation or holed up for months in a hotel room.

In desperation the other night, Louise found herself browsing Rightmove – a futile search for an affordable and accessible private rental. Before illness struck, Louise was earning a decent wage at John Lewis but now her only income is her disability benefits: nothing close to what she’d need for market rent. “They’re about £900 a month round here,” she says. “I’d have about a tenner a month to live on.”

A week after I first speak to Louise the council says adaptations, including a permanent ramp to the front door and a wet room, have now been approved and that all efforts are being made. But they cannot say either when the work will start or how long it will take. Louise has been told by a surveyor that the ramp is a “massive job”: a zigzag ramp going back and forth over the steep slope.

In the meantime, the closest Louise can get to the outside world is seeing it through glass. “I can go by the window and get in some sun,” she tells me.

She has been unwell over the weekend – the stress makes her heart condition worse – but hasn’t been to the doctor because she physically can’t get out. Louise admits she’s thought about writing to the prime minister in the hope someone will listen to her. “That’s how bad it is,” she says. “I’m in hell.”

• Frances Ryan writes the Guardian’s Hardworking Britain series