I am sorry to hear you are having this issue. For the sleep score concern, there are a few things I would recommend trying initially.
Is the watch tracking sleep at all, so that you are see a graph in the watch and Connect app?
Is the watch showing as your preferred tracker in Connect? You will also want to ensure this device is not registered to more than 1 email account.
For sleep tracking, ensure battery saver is not enabled During Sleep. Menu, System, Sleep more, Ensure Battery Save During Sleep is disabled.
Be sure you are wearing the watch at least 2 hours before bed.
Do you see HR data being recorded during the sleep hours? If not, I would also recommend trying a hard reset. For this, hold the Light button until the watch shuts off, as opposed to selecting power off. Then power this on again.
