I had a similar problem but with my thumb, but it's the same type of condition I had as mine wasn't carpel tunnel either. GP kept saying it 'would sort' out, but it kept getting worse. (I'm glad you got a physio appt....something I could never get from the NHS.)
GP kept saying it would get better but might take 12-18 mos....how the heck can you care for a baby when your thumb (or wrist in your case) isn't right?
I don't mean to upset you, but fortunately my husband's company also pays for private insurance for us. On my first private appt. they gave me the steriod injection which completely took the pain away...for about 6 months,but then it came back just like earlier. When I went back, he said it would never get better without surgery. I had the surgery and needed help with DD for two weeks, but I'm fine now.
Keep fighting for good care and don't have too many steriod injections..they're not good for you and they should never tell you to keep doing that. My private dr. (interestingly who also works for NHS) told me in confidence that many women suffer becasue they don't take care of the problem. I'm not saying that you definitely need the surgery as I'm not a medical professional...another injection may take care of it for you, but if it coninues to linger...demand it be sorted sooner rather than later as you can continue to weaken it and it might get worsea cause further damage.
Good luck and know you're on my mind..I have a friend who's been in some pain for nearly 3 yrs. after having her baby...after what she learned about me and being fine now..she fought hard and is finally getting the help she needs.
Not to be self-centered, but I had to get this taken care of as I couldn't bear weight on that thumb and was in danger of dropping DD. If that's your case, fight with confidence for the help you need.