I was about to ask a similar question as I’m constantly waking up on my back!
https://www.dunelm.com/product/dorma-full-forever-v-shaped-firm-support-pillow-1000047414?defaultSkuId=30151312&branchCode=0135&utm_source=google&utm_medium=cpc&utm_campaign=QandP_Pillows-PMax_%5BGOO-LIA-QANDP-PILLOWS%5D&gad_source=1&gbraid=0AAAAADGqyX2OzEfTKqWegyIZ1H8V6de8r&gclid=EAIaIQobChMIr4m9r8bbiQMVFolQBh16mDX_EAQYASABEgL1RPD_BwE&gclsrc=aw.ds This is the one I got and they do the pillow cases for it too , I was unsure at first as lots around but didn’t want to pay loads for one so this does the job
Ive just ordered a baby bub pillow set from vinted. All the parts are washable
I got one from bellamoon and it came yesterday, honestly the best sleep I've had in months! Woke up able to walk without limping, I got the C shape that you can zip and up zip bits to suit you & can be turned into a nursing pillow. Expensive but deffo worth it x
I just got the Dorma V pillow from Dunelm £20 and it seems to be doing the job as like you I kept waking on my back