I did switch back to her cot but she stands up screaming
This isn't a reason to decide the cot was not working. The standing up and screaming at sleep time is a normal developmental stage that most babies go through. It will have been at the time when she first learnt how to pull herself from sitting to standing - yes? That's quite normal - we all go through it and come out the other side.
So if you discounted cot use on this basis, I would suggest going back to the cot. All you have done with your floor bed is replace one problem with about 5 different (and harder to resolve) problems. You're likely to have a child with more disordered sleeping with what you're currently doing.
The sides of the cot give baby a feeling of protection and security for sleep.
So, assuming you go back to the cot - your issue is baby pulling to standing and screaming? Yeah, it's a bugger. But it's solvable.
It basically comes down to repetition and consistency. Some things to consider first:
In the cot, do you use a sleeping bag? If not, I'd recommend you do. A zip up the middle one and not shoulder poppers. These make standing more difficult in the first place.
Second - can baby get herself from standing to sitting down to lying down completely independently, without your help? Play games to this effect during the day - babies learning new motor skills love instruction games and the praise/clapping at getting things right.
So teach very specific "lie down" instructions and don't help her do it. Make it a game - sit down (yey, big claps and smiles). Now lie down (clap clap). Andddddddddd (pause) stand up!
You get the idea. You want her to want to understand and follow your instructions on movements like this. And to be physically able to do them without any help.
Those things in place - sleeping bag, physical motor skill development and cognitive ability to follow the instruction "lie down". Also the willingness to follow instruction - by getting happy over the top praise every single time the does.
Now at bedtime in the cot, it's just about consistency and repetition. After normal bedtime routine you put baby in cot standing up and give the instruction "lie down" and wait for her to follow the instruction.
Then have a mantra you repeat. For example "It's sleep time now. We lie down quietly to sleep. Nan night".
Then wait by the cot. If she stands, tap the cot mattress, tell her to lie down and wait. Repeat the instruction and bed to tap the cot mattress again, wait while she cognitively processes it. With enough game playing and praise through the days, toddlers do inherently want to please.
Praise when she lies down. Then repeat mantra: "It's sleep time now. We lie down quietly to sleep. Nan night". If she doesn't lie down, pick her up and lie her down and repeat the mantra.
A firm hand placed on her chest as she goes to sleep will both reassure her that you are there and close, and also encourage stillness. Babies don't inherently know they need to be still and calm to go to sleep, it's a learnt thing. You need to teach it.
Repeat over and over again. No matter how many times she repeatedly stands up - keep your cool and be consistent: Tap mattress, get her to lie down herself, say sleep mantra, put your hand on her chest while she settles and wait. Over and over again - every night the same, every naptime the same, always the same expectations, always the same things happening of she stands.
Repetition and consistency - these are central skills in parenting a toddler and teaching new skills.
It'll take 2 or 3 weeks to see consistency change, but you'll get there.