Proof of residency for Naturalisation - not working, not claiming benefits

Hi, any advice much appreciated.
I am struggling with documents for two of the five years I require for proof of residency. After two years' employment I started my own Limited Company, but didn't make a profit or pay myself a salary until two years later. For these initial two years I don't have any official documents. Any correspondence from HMRC or Company House went to my company's registered address, not my home address. I didn't register for self assessment as I was a company director and not earning at the time.
I have received Child Benefit during that time, but I could only evidence this through bank statements, and the online guidance states that bank statements and utility bills are not accepted as proof.
I have a generic letter from the NHS that states that I was registered with my GP for the last 10 years.

Not sure what else I could use?

Thousand thanks for your help.