Maybe you need to change the location of the bed, or the fabric or cotton quality of your sheets. Put pillows between you and your partner that allow you to have a good night sleep.
Sleeping in a cooler environment has many benefits – Not only do you generally feel more relaxed but it would solve your issue regarding feeling hot. Another benefit is that sleeping in a colder environment has been proven to make you fall asleep quicker, and make you sleep deeper so you'd be less likely to wake up during the night and perhaps having trouble then falling asleep again. Other than this it maybe worth telling your partner if they're not already aware. So try this as well as do some research on tips for falling asleep. Longer sleep as countless benefits and I'm sure you'll be feeling better in no time!! Hope this has helped! 🙂
A bigger bed helped my partner that was 6ft6' as they were able to be fully supported by the bed, head to toe. We then had separate duvets. They had a king cuz they liked to be fully cocooned whereas I had a single as I like to cuddle up but then if I get too hot I like to take the duvet off or just stick out a foot. I believe it's common in Europe to have two single beds that are pushed tohether and duvet which poppers together down the centre of the duvet so can be split into two separate single duvets.
Are you sure the only reason you can't sleep is this? I would try sleeping alone for a night or two, if you're partner agrees. You might think you can't sleep because this but really it might be something else. But try that if you want, then if you sleep fine there try go back to sleeping with your partner, if you can't sleep then yes I would try a different bed. If you still can't sleep alone dig deep into reasons why maybe you can't. See someone if you wish